MacBook's Wireless range diminished
Let's say X is the old wireless range. When the laptop is within 1/2X, the internet works perfectly. When I am at distance X, the network doesn't appear. When I am at 3/4X and try to connect to the network, I get "Connection timeout" notices. Sometimes after I enter in my password and click "Connect," the "Network Preferences" window reloads the password prompt dialog box, with an empty password. If I turn off the AirPort and turn it back on, the network often fails to appear unless I move back to within 1/2X.
The wireless router is 3Com, with WEP encryption. I am 99% sure that the problem is with my computer, because my brother's similar black Macbook gets wireless in the old areas with no problems. I'm using 8.8.8.8 and 8.8.4.4 for DNS.
I've tried: Forgetting the wireless network and then reconnecting to it, powering off and on the router, manually entering the network name and password, and none of these steps has worked. I would appreciate if you could tell me other steps I can take to troubleshoot the problem, including possibly checking for damage to the wireless antenna. Thanks very much!
White late 2008 Macbook, Mac OS X (10.6.4)