Rated 5 out of 5 stars
You were right, I changed to a clean profile and the menu's showed fine.
However, if I turn on the round dropd menu option then the problem returns again.I did notice on my old profile that I had round dropdown menus whether I had that option turned on or off so it must be that that is causing it but I'm not sure why that option is permanently on with my old profile.
Update: The bug was an import line in my userChrome.css it must have been left over from the original noia options. when I commented that out the rounded menus went away.
Well after reading this comment I looked at the code for the "rounded menus" (former nown as "new office xp" in old Noia eXtreme) option and found that nasty text shadow bug. Try rounded menus again. ;-)