XPS M1530 Wireless oddities

Hi

Hope this is the correct place to ask this. Have had a search and found endless reports of wireless problems with my model and similar Dell laptops, but usually about dropping connectivity.

I have a Dell XPS M1530 laptop (a few years old), and a Dell inspiron Mini (new)

They both connect wirelessly to a 3Com ADSL 11g wireless firewall router.

When I got the Inspiron Mini I found I absolutely could not connect it if the 3Com router was configured for WEP encryption. I did a bit of Googling and the answer seemed to be use WPA instead. I changed this on the router and the Inspiron Mini connected straight away.

I've now found that my XPS M1530 won't connect if the router is configured for WPA... Great :emotion-2: whichever option I pick one machine won't connect.

The router gives me WPK-SPK / WEP 64 bit / WEP 128 bit / WPK (with Radius server) options. In summary:

Dell Inspiron Mini + Router configured WEP (64 or 128) = no connectivity
Dell Inspiron Mini + Router configured WPA-SPK = connectivity
Dell XPS 1530 + Router confgured WEP (64 or 128) = connectivity
Dell XPS 1530 + Router configured WPA-SPK = no connectvity
And my Mac with 3rd party Airport card = works regardless of WEP / WPA

I've tried different channels, I've tried toggling between 11b / 11g and mixed. But nothing will make either the Mini connect if the router is set to WEP or the XPS connect if the router is set to WPA.

Both Dell machines are running Windows 7 Ultimate with all updates. The XPS has the Intel Wireless WiFi Link 4965AGN card.

When set to WPA (which I'm gonig to have to stick with because I use the Mini much more than the XPS) the Windows Wireless Network Connection shows my wireless network, shows it as valid with good signal strength, when I go to connect it prompts me for the security key which it appears to accept, this window then vanishes as if the connection is being made and then an entirely unhelpful box pops up saying "Windows was unable to connect to 3Com".

I guess this could be an issue with the router (which has the latest firmware). But I'm trying to eliminate things.

Does anybody know of any issues with this network card in the XPS M1530 and using WPA encryption?

Alternatively I'll end up sticking a USB wireless dongle in the XPS and disabling the built-in wireless card. Which seems a naff solution, but given this machine was effectively obsolete when Windows 7 came out and half the hardware devices weren't officially supported (only 18 months after I bought it) I wouldn't be very surprised if this was the only option.

Any advice and pointers very gratefully received.

Thanks,
Simon