* EDIT *
do not use the eqw.dll inside the eqfix.zip
* EDIT*
Here's a zip file that you can use to roll back your EverQuest if you patched it recently, it allows you to play on 3.11 servers..
Just unzip eqfix.zip to your EverQuest directory, and overwrite any existing files..
* note *
it may not work for everyone because EverQuest is just stupid...
EQEmu Fix 3.11 (win32)