diff --git a/lib/galaxy/datatypes/xml.py b/lib/galaxy/datatypes/xml.py
index d9e659bd70c..ef1f1623e28 100644
--- a/lib/galaxy/datatypes/xml.py
+++ b/lib/galaxy/datatypes/xml.py
@@ -104,13 +104,41 @@ class BlastXml( GenericXml ):
         for f in split_files:
             h = open(f)
             body = False
-            header = []
+            header = h.readline()
+            if not header:
+                out.close()
+                h.close()
+                raise ValueError("BLAST XML file %s was empty" % f)
+            if header.strip() != '<?xml version="1.0"?>':
+                out.write(header) #for diagnosis
+                out.close()
+                h.close()
+                raise ValueError("%s is not an XML file!" % f)
+            line = h.readline()
+            header += line
+            if line.strip() not in ['<!DOCTYPE BlastOutput PUBLIC "-//NCBI//NCBI BlastOutput/EN" "http://www.ncbi.nlm.nih.gov/dtd/NCBI_BlastOutput.dtd">',
+                                    '<!DOCTYPE BlastOutput PUBLIC "-//NCBI//NCBI BlastOutput/EN" "NCBI_BlastOutput.dtd">']:
+                out.write(header) #for diagnosis
+                out.close()
+                h.close()
+                raise ValueError("%s is not a BLAST XML file!" % f)
             while True:
                 line = h.readline()
-                header.append(line)
+                if not line:
+                    out.write(header) #for diagnosis
+                    out.close()
+                    h.close()
+                    raise ValueError("BLAST XML file %s ended prematurely" % f)
+                header += line
                 if "<Iteration>" in line:
                     break
-            header = "".join(header)
+                if len(header) > 10000:
+                    #Something has gone wrong, don't load too much into memory!
+                    #Write what we have to the merged file for diagnostics
+                    out.write(header)
+                    out.close()
+                    h.close()
+                    raise ValueError("BLAST XML file %s has too long a header!" % f)
             if "<BlastOutput>" not in header:
                 out.close()
                 h.close()
diff --git a/scripts/check_python.py b/scripts/check_python.py
index 15017c9d2c0..e6fdc00a7c0 100644
--- a/scripts/check_python.py
+++ b/scripts/check_python.py
@@ -1,14 +1,14 @@
 import os, sys
 
 msg = """ERROR: Your Python version is: %s
-Galaxy is currently supported on Python 2.4, 2.5 and 2.6.  To run Galaxy,
+Galaxy is currently supported on Python 2.5, 2.6 and 2.7.  To run Galaxy,
 please download and install a supported version from python.org.  If a
 supported version is installed but is not your default, getgalaxy.org
 contains instructions on how to force Galaxy to use a different version.""" % sys.version[:3]
 
 def check_python():
     try:
-        assert sys.version_info[:2] >= ( 2, 4 ) and sys.version_info[:2] <= ( 2, 7 )
+        assert sys.version_info[:2] >= ( 2, 5 ) and sys.version_info[:2] <= ( 2, 7 )
     except AssertionError:
         print >>sys.stderr, msg
         raise
diff --git a/tools/ncbi_blast_plus/ncbi_blastn_wrapper.xml b/tools/ncbi_blast_plus/ncbi_blastn_wrapper.xml
index dbefac05d6e..6b942380403 100644
--- a/tools/ncbi_blast_plus/ncbi_blastn_wrapper.xml
+++ b/tools/ncbi_blast_plus/ncbi_blastn_wrapper.xml
@@ -1,6 +1,6 @@
 <tool id="ncbi_blastn_wrapper" name="NCBI BLAST+ blastn" version="0.0.11">
     <description>Search nucleotide database with nucleotide query sequence(s)</description>
-    <!-- If job splitting is enabled, break up the query file into batches of 500 sequences -->
+    <!-- If job splitting is enabled, break up the query file into four -->
     <parallelism method="multi" split_inputs="query" split_mode="number_of_parts" split_size="4" shared_inputs="subject" merge_outputs="output1"></parallelism>
     <version_command>blastn -version</version_command>
     <command interpreter="python">hide_stderr.py
diff --git a/tools/ncbi_blast_plus/ncbi_blastp_wrapper.xml b/tools/ncbi_blast_plus/ncbi_blastp_wrapper.xml
index 0f7d0a7c8ee..17dda06e5e1 100644
--- a/tools/ncbi_blast_plus/ncbi_blastp_wrapper.xml
+++ b/tools/ncbi_blast_plus/ncbi_blastp_wrapper.xml
@@ -1,6 +1,6 @@
 <tool id="ncbi_blastp_wrapper" name="NCBI BLAST+ blastp" version="0.0.11">
     <description>Search protein database with protein query sequence(s)</description>
-    <!-- If job splitting is enabled, break up the query file into batches of 500 sequences -->
+    <!-- If job splitting is enabled, break up the query file into four -->
     <parallelism method="multi" split_inputs="query" split_mode="number_of_parts" split_size="4" shared_inputs="subject" merge_outputs="output1"></parallelism>
     <version_command>blastp -version</version_command>
     <command interpreter="python">hide_stderr.py
diff --git a/tools/ncbi_blast_plus/ncbi_blastx_wrapper.xml b/tools/ncbi_blast_plus/ncbi_blastx_wrapper.xml
index cda16a5f34f..487c433ee1b 100644
--- a/tools/ncbi_blast_plus/ncbi_blastx_wrapper.xml
+++ b/tools/ncbi_blast_plus/ncbi_blastx_wrapper.xml
@@ -1,6 +1,6 @@
 <tool id="ncbi_blastx_wrapper" name="NCBI BLAST+ blastx" version="0.0.11">
     <description>Search protein database with translated nucleotide query sequence(s)</description>
-    <!-- If job splitting is enabled, break up the query file into batches of 500 sequences -->
+    <!-- If job splitting is enabled, break up the query file into four -->
     <parallelism method="multi" split_inputs="query" split_mode="number_of_parts" split_size="4" shared_inputs="subject" merge_outputs="output1"></parallelism>
     <version_command>blastx -version</version_command>
     <command interpreter="python">hide_stderr.py
diff --git a/tools/ncbi_blast_plus/ncbi_tblastn_wrapper.xml b/tools/ncbi_blast_plus/ncbi_tblastn_wrapper.xml
index 2d6ece29b92..73cead395d8 100644
--- a/tools/ncbi_blast_plus/ncbi_tblastn_wrapper.xml
+++ b/tools/ncbi_blast_plus/ncbi_tblastn_wrapper.xml
@@ -1,6 +1,6 @@
 <tool id="ncbi_tblastn_wrapper" name="NCBI BLAST+ tblastn" version="0.0.11">
     <description>Search translated nucleotide database with protein query sequence(s)</description>
-    <!-- If job splitting is enabled, break up the query file into batches of 500 sequences -->
+    <!-- If job splitting is enabled, break up the query file into four -->
     <parallelism method="multi" split_inputs="query" split_mode="number_of_parts" split_size="4" shared_inputs="subject" merge_outputs="output1"></parallelism>
     <version_command>tblastn -version</version_command>
     <command interpreter="python">hide_stderr.py
diff --git a/tools/ncbi_blast_plus/ncbi_tblastx_wrapper.xml b/tools/ncbi_blast_plus/ncbi_tblastx_wrapper.xml
index e65ed289bd4..bb96f972a9c 100644
--- a/tools/ncbi_blast_plus/ncbi_tblastx_wrapper.xml
+++ b/tools/ncbi_blast_plus/ncbi_tblastx_wrapper.xml
@@ -1,6 +1,6 @@
 <tool id="ncbi_tblastx_wrapper" name="NCBI BLAST+ tblastx" version="0.0.11">
     <description>Search translated nucleotide database with translated nucleotide query sequence(s)</description>
-    <!-- If job splitting is enabled, break up the query file into batches of 500 sequences -->
+    <!-- If job splitting is enabled, break up the query file into four -->
     <parallelism method="multi" split_inputs="query" split_mode="number_of_parts" split_size="4" shared_inputs="subject" merge_outputs="output1"></parallelism>
     <version_command>tblastx -version</version_command>
     <command interpreter="python">hide_stderr.py