Yay for patch days.

[JPaterson]

Okay, one question: I can no longer see chat of any kind in my chat box. Guild, tells, general, custom channels, nothing.

Only chat mod I use is Prat 2.0, which I disabled, but still can't see anything.

Any ideas what other addons might be causing this?

[kall]

Your chat settings are cached in a .txt file in your cache directory if I recall correctly.

Try copying it somewhere and deleting it, then restarting WoW.

[swaldman]

Okay, one question: I can no longer see chat of any kind in my chat box. Guild, tells, general, custom channels, nothing.

Only chat mod I use is Prat 2.0, which I disabled, but still can't see anything.

Any ideas what other addons might be causing this?

I've just got back from holiday and found the same problem. I use an awful lot of mods, but your post has saved me removing them all... did you find a solution?
Thanks

EDIT: Solved.
For anybody else wondering, the offender turned out to be NotesUNeed. An updated version (which I hadn't found before, for some reason) has fixed things.