Ubuntu Networking :: Cannot See D-Link DIR-615

I've just installed ubuntu 11.04 on my dell inspiron mini 10; dual-booting it with Windows 7.

I've looked at a couple of other threads about problems with the wireless card in the netbook and about problems with the wireless router. However, this problem doesn't seem to be the same; the netbook can see other wireless networks, just not mine, and other people seemed to be able to access their wireless network for a short period of time before they stopped being able to access it.

I can't see the wireless network on the D-link DIR-615 at all in ubuntu, though it still works in windows 7.

I've tried reinstalling the broadcom STA drivers as per this link and reinstalling but this hasn't made any difference.

What things should I consider trying in order to resolve this?

Ps. As a side note, my other ubuntu laptop (a toshiba equium A100) cannot see this network either, but has no problem connecting to other, although oddly it couldn't detect it in windows either before I put in a new harddrive and installed ubuntu on it.