Fine in ie - content pushed to the left in firefox

[SHK]

My page looks fine in ie7, but the main content is pushed far to the left.
The only significant alteration I've done is to include a niftycube menu in the header.

Validation checks out, and I can't think of any obvious errors I've made.
But Im no expert, hence why I ask.

Anyone know whats wrong?

Thanks
/SHK

[TMC_Sherpa]

adding

#mainWrapper {
float: left;
}

brings everything back onto one page in FF, not sure what that will do to IE however

[SHK]

Site seems fine in both ie and firefox now.

Thanks for the help!

/SHK