CMS Made Simple Forums

My site http://nimeaea.s423.sureserver.com/ is all good with explorer but man, firefox makes it look like a site from ed edd and eddy, I think my css is messed up, just have a look at it , would not mind your imput..

Look atthe line events.gif and add a semi-colen ";"

It is the only erro rthat came up in css validator. It may help.