Wired/Wireless Bridge Timeouts

Hi,
Don't know if this has been solved yet, but I've seen it mentioned a good
few times before.

I have a DSL connection through a Router, wired into a Hub.
This hub is then wired into my own PC, which also has a wireless USB NIC.

Then wired and wireless NICs are bridged, and given 192.168.0.4 between
them. Everything is fine, connecting to the internet, other PCs etc.

The problem I have is that I also have a laptop with a wireless card. Its
using the Bridge on my PC to connect to the Internet. It does this happily
for about 10 minutes at a time, and then stops. Pings to the PC are fine, as
are pings to the DSL Router, but no replies from anything on the internet.
After about another 10 minutes, everything works again, until the next time.

I've tried all the suggestions I've seen so far, wireless NICs in
Compatibility Mode, disabled all Power saving on the Wired and Wireless
NICs, nothing seems to work.

If anybody has any other suggestions, I'd be really grateful.

Thanks,
Eoin