Linksys WRT54G - WinXP lost connections

I just setup a Linksys WRT54G router with 5 wireless WinXP laptops (4 use 802.11g, 1 uses 802.11B. All have internal Mini PCI cards) plus one desktop machine direct wired to the router.

I configured the router for DHCP, 128bit WEP, SSID broadcast disabled, and entered a manual 26 character HEX key for key 1).

For each laptop, WEP shared settings were used and I entered the 26 character HEX key using Windows wireless networking configuration. Each machine connected to the Net through the router successfully.

Problem: so far the 802.11b and one 802.11G laptop have failed to remember the wireless connection profile eventually and lose the ability to find the router.

Anyone have any suggestions where the problem is here?

Thanks...

Tom