I grabbed a 2.7.2 zipfile.py, and my original comments stand.  If there is a "garbage at end of file" patch, I can't find it; please provide a line number or a hint.  The user at yale.edu reports that the patch works.  Here is a diff of my changes.  To test, append some junk to a good zipfile: echo junk >> good.zip, and try reading it.  Let me know if you want me to do anything else; maybe look at 3.2; or email me offline.

*** zipfile.py	2011-12-09 11:25:07.000000000 -0500
--- ../zipfile.py	2011-12-09 05:48:00.000000000 -0500
***************
*** 237,248 ****
          recData = data[start:start+sizeEndCentDir]
          endrec = list(struct.unpack(structEndArchive, recData))
          comment = data[start+sizeEndCentDir:]
! ## Remove       # check that comment length is correct
! ## Remove       if endrec[_ECD_COMMENT_SIZE] == len(comment):
!         # check that the offset to the Central Directory points to a valid item
!         fpin.seek(endrec[_ECD_OFFSET], 0)
!         dat = fpin.read(4)
!         if dat == stringCentralDir:
              # Append the archive comment and start offset
              endrec.append(comment)
              endrec.append(maxCommentStart + start)