Intermittent problem on Wireless Network

Hi
I have a Netgear DG834G Wireless ADSL router on the middle floor of 3. I
have 4 computers connected via wireless on 3 floors of my house.

First computer is Compaq laptop with inbuilt wireless-G port. This one
has no problems and gets good/excellent signal strength throughout the
house.

Second computer is a desktop on top floor with a Linksys Wireless G PCI
card WMP54G. This also has no problems.

Third computer is a desktop in another room on top floor. This has a
Netgear WG311 PCI card. This one works for a while, maybe 10 minutes
maybe 1 hour, but then is unable to access the internet. However the
wireless icon in the system tray claims it is still connected and has a
good signal strength. Internet connection can only be reestablished by
using the repair option (right click on system tray wireless icon).

Fourth computer has same card as third and has same symptoms.

All computers are running XP and have up to date drivers.

I thought that if one of the computers lost the wireless signal (due to
interference or whatever) it should reestablish connection automatically
but this does not seem to be happening. My feeling is that there is
something wrong in the settings of the Netgear PCI cards but I am not
sure what to try next. Any suggestions?

thanks
Martin

I have a different Netgear card in a different PC, but here was my
problem and my solution....

Card would sometimes lock up PC, especially if PC was unused for more
than a few minutes. Turns out my model Netgear card has a problem with
PCMCIA bus power management. Once I told the PC to disable power
management of the PCMCIA bus, the problem went away.

Hope this helps.