bug in uploading to chess.com/downloads

I have uploaded 2 programs (GuessTheMove, and ConvertChessboardImage).  In both cases, when I try and upload a new version, I do not get an error, but subsequent attempts to download give a message "file is corrupted".  This forces me to delete the program from chess.com and then upload it as if it were new.  That loses the existing comments, votes, and download counter.  I suggest that you fix the bug so that I can upload fixes and enhancements.  Furthermore, I think the new version should be given an new upload date (so that it appears first in the "most recent" order), along with all the old comments, votes, and download counter.  With the current system it is difficult to post enhancements and bug fixes to existing material.