Vostro 1700 wireless keeps going and needs a system reboot - any ideas?

Hi guys
I have two seperate questions to ask, so will post them seperately.

This issue isn't unique to me, as a friend also bought a Vostro 1700 at the same time as me, although I have the Intel 4965AGN wifi card and he has the equivalent .11b/g card.

Basically, randomly (but usually once a day or so) I can no longer access the internet. IE stops connecting, and from then the system slows right down. The only way to fix it is to reboot, but for some reason it takes about 10 mins to shut down (and doesn't always shut down). It's only when this happens that it takes so long to reboot.

I've tried searching for the network, but it can't find any, and the little wife icon in the right corner have a red cross through. My friend's does exaclty the same thing. I've updated the BIOS to A07 and also upgraded the wifi drivers, but it's still doing it.

Does anyone have any ideas why it's doing it?

Many thanks.

 

The thing's done it again! Having to post from my desktop as the Vostro is converting something so I can't reboot yet!

One thing I forgot to add, which may be important, is that I can still access my home network (ie drives on the network and my NAS), and I can still get emails. It seems to be only certain things I can't do. Neither IE nor Firefox will connect, so it's not only IE.

Thanks.