I'd be prepared to bet (although not with real money) that your "core.ini"
file is actually called "core.ini.sample". If you can't ever remember
changing it then it's definitely still wrong. The file installed by the GPL
1.2 patch will not be read by GPL. It has to be changed.
It's possible that windows is hiding the ".sample" extension. As Paul
Thurston suggested, find your GPL folder and right click on the "core.ini"
file and select 'properties'. Look under MS-DOS name. If it's not
"core.ini" then it still needs changing. Right-click and 'rename' it. You
can also turn off file extension hiding (can't remember how to do that in
98se, I use ME).
Every time someone has trouble getting FF to work in GPL, it is *always* the
same problem, it's always that they haven't renamed that file correctly.
Like I said, if you can't remember renaming it, then it's still wrong.
Good luck :)