I'm having some problems setting up a new wireless PCI card on a WinXP SP3 PC.

I know that the router is configured correctly. It is a Linksys WRT54GL, using 802.11b/g. Security mode is WPA2 Personal with TKIP+AES encryption. I am able to connect to this fine using my laptop (first gen MacBook with a 802.11b built in card).

The new PCI card is also Linksys, but it supports 802.11n. Card seems to be installed ok (Windows sees it fine, doesn't list any errors in Device Manager), however when it scans for available wireless networks it can't find my wireless network (the router is set to broadcast the SSID).

I tried to enter the network SSID manually, but that didn't seem to help. I chose WPA2-PSK for network authentication. The only options for encryption are TKIP or AES - I've tried both, neither worked. I am sure that I typed in my wireless key correctly.

At this point, I don't think the problem is with encryption, but something else. It almost seems like I need to switch the wireless card into g mode, but I haven't found a way to do that (if that is even possible/necessary - I thought n was fully backwards compatible with g).

Also, the PC is in the same room as the router, and my laptop, so I don't think that it is an interference issue.

Any ideas what I'm doing wrong? I'm running out of things to try at this point. :(