I uninstalled Toribash 4.1, installed 4.3, set it in my firewall to be allowed connections, copied the old login.dat, and can't connect to any server (the lobby shows up, but on clicking any room I get 'not connected). Deleted login.dat, logged in, still the same.

Also, if I 'esc' from 'not connected' to bring up main menu and click multiplayer, the game crashes.

Are the servers down or am I having connection problems?

I'm having the same problem, i only got Toribash a couple days ago and was looking forward to the multiplayer but every time i try that happens.
I also found out (this works for me anyways) if i challenge uke after trying to go online then go multiplayer again it won't freeze/crash

It didn't help me, instead it froze again.

If the game's crashing on the multiplayer menu then there's more causing the problem than just the game.

Can you provide info on your machine?

Sure.

Win 7 x64 Professional
Intel Core i5 @ 2.30 Ghz
4.00 GB RAM

AMD Radeon HD 6630 M/ Intel HD Graphics (Toribash is using the latter, I haven't been able to force CCC to make Toribash use Radeon - CCC simply bugs out on me, but reinstalling it is such a hassle that I simply get by)

Any other games works fine. I haven't tried 256 color mode in Toribash yet, I have connectivity problems today in general

EDIT: Since it's the same machine Toribash 4.1 worked fine with, and I haven't changed firewall settings either, I suppose I messed up the uninstallation or installation...

Having the same problem. Not that into computer parts but the top part seemed to be exactly like what i ordered.

"Win 7 x64 Professional
Intel Core i5 @ 2.30 Ghz
4.00 GB RAM"

Give the Intel graphics driver an update. No guarantees but the TB problems are pretty much fixed now so long as they're up to date.

Mr lazy ATI should just update that instead ;)