You no longer have copies of the files generated by the 1.3a patch. You restored the backup REZ files to the 'data' folder. However, even after doing that you game does not run correctly.Yeah. you'll have to re-install. Your saves and minisaves should be safe, but you might want to make backup copies in different folders just to make sure.
I'd be interested in seeing your DATA.REZ file. You don't *have* to zip the file; it's already pretty small, and email doesn't object to the REZ extension.
What anti-virus and firewall programs do you use? What file system does your hard drive use (FAT32 or NTFS)? To learn the answer to this second question, right-click on your drive in an Explorer window and choose Properties. The third line reports the files system. Thanks.