Sorry to reply so late. This is a bug. The workaround below satisfied my needs (10.1). Others (esri link) suggested using a Describe, but I found that too slow and unnecessary.
for FC in bugListFeatureClasses("filter","feature type","feature dataset"):
def bugListFeatureClasses(wildCard, fType, FD):
Uses current workspace
This is required because a 4 YEAR OLD BUG in arcpy still exists.
arcpy.ListFeatureClasses() returns rasters
Arc10 + SQL Server = apparently too complicated for Esri
http://support.esri.com/en/bugs/nimbus/TklNMDYyMDc0 (must sign in first)
badFCList = arcpy.ListFeatureClasses(wildCard,fType,FD)
rasList = [x.lower() for x in arcpy.ListRasters()]
goodFCList = 
for FC in badFCList:
if FC.lower() not in rasList: