If you're having problems with TrueMobile 1400...

Try lowering the channel set at the access point to be below 11.

I have two 3Com OfficeConnect (802.11a/b/g) access points at home, and while configuring my new Inspiron 5150 w/TrueMobile 1400 I didn't manage to detect any of the two networks. The channels were set to 12 and 13. I could however detect other networks in my neighbourhood. I read an article on 3Com's knowledge base about an iPaq not being able to connect to a wireless network, and the solution was to lower the channel set at the access point to be below 11. I reconfigured my access points so that they used channel 1 and 2 respectively. That solved my problem. Seems the TrueMobile 1400 card is unable to connect to networks with channels higher than 10. At least thats the case with my 3Com access point.

I hope this information is of some use...

/knut