Airport can\'t \"see\" network

[dmojo13]

Greetings! Hope someone can help... this one has me baffled. Been a mac dude for quiet a while, but always like learning. Using latest OSX op.system. Using older Airport cards (802.11b) in an iBook and a G4 tower. Have a 3 year old Microsoft wireless router, MS-500 (yes, I know... evil!) but it's always worked with my broadband connection. I just moved locations into an apartment complex. There was only one other person who had a wireless signal being broadcast that my airport could see. Everything worked fine with my airport seeing my network just as it used to for a week. Then one day my network name was not visible from the airport pull down menu. But I could still see that other person's network. Just not mine. Wierd!

I tried everything. Restarting the cable modem, the wireless router... etc. No luck. Then after a week of nothing. All of a sudden, my network name popped back up on the airport menu and everything worked again!

WEIRD! Now, another 10 days later, it's gone back to not working. Any ideas what might be going on? I feel like I'm missing something. Is my wireless router going bad? (FYI: My bro with a new Linksys Wireless G router even had this same problem recently with his old Ti book and an 802.11b card) Is it an issue with OS 10.4.3? An issue with the older Airport cards or just the nature of 802.11b? I did upgrade about the time this all happened. I'm baffled just because it's always been very reliable. It's a small aptartment and I did get a good signal when I had it working. HELP! What's going on? - Many thanks!