diff --git a/lib/galaxy/visualization/data_providers/genome.py b/lib/galaxy/visualization/data_providers/genome.py
index b1915691407..fc5da2774f2 100644
--- a/lib/galaxy/visualization/data_providers/genome.py
+++ b/lib/galaxy/visualization/data_providers/genome.py
@@ -195,7 +195,6 @@ class GenomeDataProvider( BaseDataProvider ):
         except AttributeError:
             # FIXME: some data providers do not have a close function implemented.
             # Providers without a close function include:
-            #  pysam Tabixfile
             #  bx IntervalIndex
             pass
 
@@ -346,13 +345,16 @@ class TabixDataProvider( FilterableMixin, GenomeDataProvider ):
 
     def open_data_file( self ):
         return ctabix.Tabixfile(self.dependencies['bgzip'].file_name,
-                                index_filename=self.converted_dataset.file_name)
+                                index=self.converted_dataset.file_name)
 
     def get_iterator( self, data_file, chrom, start, end, **kwargs ):
-        start, end = int(start), int(end)
+        # chrom must be a string, start/end integers.
+        # in previous versions of pysam, unicode was accepted for chrom, but not in 8.4
+        chrom = str(chrom)
+        start = int(start)
+        end = int(end)
         if end >= (2 << 29):
             end = (2 << 29 - 1)  # Tabix-enforced maximum
-
         # Get iterator using either naming scheme.
         iterator = iter( [] )
         if chrom in data_file.contigs:
diff --git a/lib/galaxy/webapps/galaxy/api/quotas.py b/lib/galaxy/webapps/galaxy/api/quotas.py
index 4a5ed045b3e..1403f09ab47 100644
--- a/lib/galaxy/webapps/galaxy/api/quotas.py
+++ b/lib/galaxy/webapps/galaxy/api/quotas.py
@@ -50,7 +50,7 @@ class QuotaAPIController( BaseAPIController, Admin, AdminActions, UsesQuotaMixin
         Displays information about a quota.
         """
         quota = self.get_quota( trans, id, deleted=util.string_as_bool( deleted ) )
-        return quota.to_dict( view='element', value_mapper={ 'id': trans.security.encode_id } )
+        return quota.to_dict( view='element', value_mapper={ 'id': trans.security.encode_id, 'total_disk_usage': float } )
 
     @web.expose_api
     @web.require_admin