At the end of SoA your pc becomes immune to +1 weapons and lower. When I started ToB I kept getting hit by a mage who had a +1 Quarterstaff...whats up with that???? :rolling:

That's not true. I believe that it is only immunity to normal weapons that you receive. Which means that any magic weapon can hurt you, including +1 enchanted ones.

What i do find a bugger is when pretty much all your characters BUT minsc have + 1 weapons or normal weapons and they can't do jack s**t!

If you take the good path in Hell you gain Immunity to +1 weapons and less.
If you took the Evil route you get +2 to CON.

So Recoil Suave, your information is false, I would venture a guess that it may be a bug, but it may have not be impemented in BG2:TOB.
It doesnt do you much good, as most people have +2 or better weapons.

I read somewhere that there's a bug which doesn't let you keep the abilities you got in hell if you import a character (or was it game?) into ToB. So, how bout it? Do you have the other hell abilities (magic resistance and whatnot) or are those lost as well?

Vukodlak, it is not a bug that you speak of. When you import a game into TOB for SOA it imports before you gain the abilities, there is no way to have them, unless you go through the final fight with Irenicus in Hell and then you are transported to the area with the statue heads.
To go further with Vukodlaks question, did you import into TOB, or did you go through the final fight with Irenicus?