If you do have a secure backup of the wallet file why don't you research that issue?
Try re-installing 5.2 again. You have nothing to lose but a bit of time.
I strongly believe that your "bug" amounts to a typo, caps lock being turned on or some other trivial matter.Doing backups of an unencrypted wallet is an insanely wrong idea.
The only worse thing that comes to mind is never bothering with any kind of backups at all.
It's critically important that you only download the client from a trusted source, like the Bitcoin homepage
. It will redirect you to sourceforge for the actual download.
Never download from random sites, rapidshare, or bit-torrent as it well could be booby-trapped.