This is not uncommon if the makes are dissimilar or the firmware drivers are not the latest.
I can't figure this one out. I have a Linksys WRT55AG router networking three computers via wireless. I had absoutely no problem setting up WEP on two of the machines (1. Laptop with built in adapter and Win 2000, 2. PC with WMP54G and XP SP2), but after woriking it for a week I still can't get my third machine (PC with WMP55AG and XP SP2) to connect when WEP is active. Signal is not an issue, the PC is within 15 feet of the router. Any ideas?