Fallout 3 will not load at all. Just tried.
You didn't by any chance get your copy of Fallout 3 from Direct2Drive, did you? If you did, then FOSE is incompatible and you'll have to uninstall it.
Check your fallout 3 folder, where your .exe file and the fose loader file are located, and locate the fose.log and fose_loader.log files. Open these up in Notepad and check them for error messages. You could copy and paste them here onto the forum as well - it might help with troubleshooting.
I feel bad about this - I got you into this mess.
I'll do as much as I can to get you out of it.