WoW - Disappearing Chat WindowsFollow

I have a problem that is seemingly afflicting other people but we have no idea what causes it.

All my custom chat windows in the game disappear randomly for no reason. One second they're there, the next they're simply gone. I line my windows up side-by side along the bottom where the default window is and create a new window to hold the general world channels and such as well as show Rep, EXP, loot and a few other things. The thing is, this window keeps disappearing on me. No matter how I set it up, lock it, rename it, make it so it shows whispers and such, it keeps disappearing. Even stranger, it will still disappear when I keep it "hidden" in behind the genral window alongside my combat window.

I contacted Blizzard and all they said that it was probably a UI problem and to uninstall everything. Thing is, I got a new computer and copied over my old Interface folder and dropped it in. I have downloaded newer versions - CT Raid, Titan, Outfitter, but nothing new or usnusual. FlagRSP, but I haven't touched or updated that or even loaded it in months. I have other files in there called MI2_various file names and I'm not sure what they are, but if they aren't part of one of the above I will delete them.

Has anyone else had this problem or know how to fix it? It's terribly frustrating.

I'll try it, thanks. Though I am just considering deleteing my AddOns folder and re-downloading everything to see if that fixes the problem. I doubt it, since that's all Blizzard ever says to do to fix stuff, but I'll try. Yours first.