8
I just can't seem to find the post that included what I did to get rid of it however I now remember it had to do with the multiblock hack and a php echo being in the code twice.
What version of XOOPS are you running? Have you made any hacks recently just before you noticed this mysterious "f". (mine was a 1, btw) ?
Did you add any new module(s) just before this started happening? If so-try deactivating them one at a time and check to see if the "f" still shows.
If that doesn't do it then I would download a fresh version of the XOOPS from a different location than I got it from the first time and re-upload the modules/SYSTEM folder overiding the one that is there and check to see if that solves the problem.
The reason I suggest the Systerm folder is because it apprears the "f" is showing up in all of the system functions. It is in your Register Here too.
"Always backup your site and database first"
HTHs
Quest