I sometimes also have this behaviour that my 3G says it's connected but doesn't actually do anything.

Rebooting solves it. But also going off-line (flight mode) and re-enabling the radios.

That's my solution. And a lot quicker then rebooting.

Hinderance indeed. But not as much as other Symbian stuff I had to give up on due to going to N900.

Still loving my n900, although I sometimes feel like a madman preaching in the desert when I'm trying to convince other people of it's virtues.