WPNT834 range problems

[CasaDelGato]

I have a WPNT834 in my house, and a NetGear PCI 802.11b card (forgot model #) in a computer at my moms house about 200' away.
I used to get a fairly reliable but weak signal at the computer, which was plenty for her to read her email.
I don't get any signal anymore. As far as I can tell, the only change has been the recent upgrade in the router's firmware to V1.0_51 NA.

I've even tried one of the Hawking HSB2 range extenders, and it doesn't seem to make any difference. I get NO signal at the remote computer.

Any suggestions on what else to check?

[Sop1]

I don't know about the WPN834 but the WNR854T has an option to either optimize N devices for speed or to optimize for mixed b/g/n environments which lowers the speed of the over all connection (which should not be a factor). I would think this would help pick up that b device at your moms perhaps. ???

[CasaDelGato]

I already have the router configured for max range instead of max speed.
My (new) laptop gets a weak but useable signal at my moms. Her computer still gets none.
I just bought a brand new NetGear wireless USB device, it doesn't get any signal at her computer either. I'm going to stick it on a 10' cable and see if I can put it outside her window. (My laptop gets a good signal there.)

[CasaDelGato]

Okay, now things are getting REALLY weird.
I brought my Moms PC back to my house. It is now sitting about 8' away from the WPNT834 router.
No Signal. On either the WPNT111 (USB device) or WG311T (PCI card).
They both find the hardware, they just don't find any wireless networks.
My 2 laptops sitting on the same desk find the wireless network just fine, with excellent signal strength.
The WPNT111 is brand new, never before used!