Belkin or TP-Link USB at fault?

[Bane]

This problem has only recently started when connecting by wi-fi once router has been on for a while. Don't think it happens the first time, but later attempts since PC was turned off.

Laptops with Intel wireless have no problem connecting.

Once issue occurred for desktop PC I installed TP-Link USB on a laptop (win7 64-bit) and it suffered same issue as desktop PC (Vista 64-bit). Turning router off and back on allowed the adaptor to connect and get internet access.

Will get some pictures next time it happens. But from memory when broken the Identifying Network stage takes a while to clear, then labelled as connected to unknown device and limited to local access only. Can't bring up routers UI.

Checking router UI using a laptop it lists a DHCP entry for desktop PC.

Modem/router: Belkin F5D7634-4-H v2 (V1000 page as V2000 not listed on Belkin site) with latest firmware already on it.
USB adaptor: TP-Link TL-WN821NC v3 with driver only v8.0.0.76 from 28/07/2010

 

[Bane]

Problem returned today, stuck for a long period at Identifying network and then connecting to Local only. And not able to access router UI even though accessing with a laptop shows desktop IP is connected.

When it works the log has two entries:
09/08/2011 21:11:41 sending ACK to 192.168.2.2
09/08/2011 21:11:40 sending OFFER to 192.168.2.2

But when this issue occurs I just get the OFFER line and no ACK.

The router has DHCP lease time set to forever.