Provide your page, please.
Page is very complex to post it here. I use Facelets and a lot of decarators/compositions. I notice that error in IE6 appears only if i have rich:suggestionbox at this page, without rich:suggestionbox everything is ok in IE6, but not in FF.
Part of my page with tooltip looks like:
<h:inputText id="inputField" value="test">
<rich:toolTip value="toolTipTest" />