I remember that we've fixed the issue, but can't remind exact version. Please try 3.3.1.GA or 3.3.2-SNAPSHOT. If you cannot upgrade, then forcing IE to run in IE7 mode will fix the issue - there's solution already described on wiki in context of rich:modalPanel component as the same problem was detected there.
I'm already using version 3.3.1 GA. But I'll try a 3.3.2-SNAPSHOT. Could you give me a hint how to configure it as dependy in Maven ? For the official relase it's clear to me but how can I get it working for the snapshot ?
I've also tried the IE7-mode before - but with no success.