PaulM,
This post should actually be placed in your mod's description, somewhere...so others who are having the same issue after installing FlashChat can resolve it. It took me a day to actually find this answer. Must have been how I was going about it...
Anyhow...I know there has been a lot of issues about the popup menus from vBulletin's navbar disappearing behind the FlashChat window.
For a resolution, please see this thread located at Tufat's forum:
http://forum.tufat.com/showthread.ph...in+menu&page=2
Hope you find it useful...
You might also want to include this with your other versions of this mod, as well.