Not sure but this sounds like an issue I had and which was related to fp.dsk. FPC uses three files to store certain config parameters, fp.ini, fp.cfg and fp.dsk. They are normally in your working folder. Sometimes the IDE messes up the fp.dsk file.
Suggest you delete fp.dsk and try again. Don't worry, fp will create a new version, all you may lose is your windows list and possibly code complete list.
Second, do not start fp via a link from the desktop. Best option is to open a command shell (cmd.exe), go to your work folder and start fp from there.
I have been working with fp 2.6.4 and 3.0.1 on winXP and win 7 Pro for quite a while, and it works nicely and stable. Whenever I get a signal 291 or other strange behaviour, I delete fp.dsk and job done.