Everything seems to be working OK in an unmodified installation. But when I try to add the Google Translate code to ad_header (I want it at the top right of the forum pages) :
The popup windows that appear when you hover over a thread title in a forum no longer appear in the correct place -- the first one is at the bottom of the page and the subsequent ones don't appear at all (below the visible window?). When I switch back to the default style everything works as expected.
The same thing happens when I tried putting it in ad_above_content, or in any other ad_* except the sidebar (which isn't a workaround because it's not visible on the messages page).
Any ideas on how to fix / work around this?