_moz-rs-heading appearing in firefox and not IE

Hi,

I have a site that appears ok in IE but when it appears in Firefox it inherits _moz-rs-heading and so menu items don't appear as they should. I think a document may have some kind of word formatting that is being parsed in Firefox when the page loads.

It is overwriting my css and I am trying to find the document that has this format in its source. But I would like to know why this happens as I am developing a site for a client that is publishing the content themself.

Anybody?

Sarah