I finally got around to Googling this issue I’ve been having with my Dell E1505 laptop, which uses a Dell 1390 WLAN Minicard. Thought I blog about it since it was buried deep in a forum somewhere.
If your laptop is having issues connecting to WIFI connections, regardless of what router you’re using. Updating the drivers will not help! It is most likely an issue with whatever internal antenna the card is using. Aparently there are more than one antenna this card can use?? I’m not sure, but the problem I was having was that I would see the access point, could connect, but the connection would drop shortly thereafter. Then the access point would not be visible for 5 or 10 minutes. Using the Dell WIFI software or Windows XP Wireless Zero Configuration Utility had no impact.
To fix this issue, go to the Device Manager. Double click on the Dell Wireless (1390/1490/1500) Dual Band WLAN Mini-Card device. The properties dialog should appear. Click on the Advanced tab. Look for Antenna Diversity under the Property. Change the value to Aux. Hit ok. Then try and reconnect to your WIFI connection. By changing this you should see your access point and be able to connect to it.