Maurizio84: what exactly is the problem with the old saves?
game crashes?
game doesn't recognize/find them?
character/party messed up?
something else?
this would at least help figuring out what to do, i don't think conversion is possible unless you wish to edit every single global/party/etc stat individually which would be a pain in the ass to say the least, would be easier to just start the game from beginning.
The screen just goes black when I try to load savefiles that I generated in Windows.
DubConqueror: The easier thing to do, would be to not convert the save-files back (there's no way to do that but for handpicking each change with an editor and reverting it back - with a 99% chance of failure if you're not adept at modding and editing BG). The easy thing would be, to rescue your old WeiDu-logfile from the hard-drive BG was installed on and re-mod your Linux game in the exact same way as you did your previous install (with the exact same versions). A problem you might run in to, is not all mods being Linux-compatible I think.
I'm afraid I can't help you with the Linux-part of things, I'm stuck to Windows as gaming is my most important activity on PC and no other system can give me the same compatibility Windows can. Alas, I say.
I did try this approach, but the main problem is I don't think I got it all right. I might have picked a different resolution for the widescreen mod, and I can't remember if I included some addon mods, etc. Anyhow it produced the same result.