Is anyone else still plagued by this? I lose my combat window constantly, I suspect that it's related to one of the mods I run (SCL maybe) and it makes me want to scream since I lose it every time I zone. Is this happening to anybody not running chat log style mods?

yea, pretty sure its SimpleCombatLog. it happens to me all the time, but I can't live without SCL.

I just have a macro'd button on a sidebar

/script ChatFrame2:Show()

and click it everyitime my combat log disappears.

I know that the "Auto-join guild recruitment channel" bug is back. Disabling that kept my HitsMode window from disappearing (which defaults to frame7, btw)

AFAIK, it causes any non-docked windows to disappear.

If SCL is still causing chat frames to vanish, just go to your Interface --> Advanced options and set the chat frames to Locked.

I had this problem, it was the above mentioned "auto-join guild recruitment channel" bug as well. Disabled that, problem solved.

I don't think this is related to any mods. It used to happen to me and as others have said, disabling auto-join guild recruitment channel fixed it.

Yep, disabling the auto-join fixed it. Very stupid bug.

I don't see what this has to do with Auto-join, this bug used to happen to me long before the Guild Recruitment channel existed. Locking the chat interface seems to prevent it from happening, and as a precaution, I back up my WTF folder after I make any changes to my UI.

There was a bug prior to the AJGR bug that had the same effect, but I don't recall what it was.

Apart from the auto-join portion of the bug, I have also related this occurance to opening the world map. For awhile a few months back, occasionally when I opened my world map inside a battleground (very rarely outside a BG also), my combat log would get erased. Locking the chat windows via the interface option worked, but since TBC I've noticed another interesting thing. I'm not sure if this is addon-related, but sometimes if I open my world map JUST as I am put into combat, it will end up toggling the "display UI" function. Not a bit deal, just re-toggle it with whatever key you have it bound to, but its interesting/strange that the world map has so many issues.