As usual, Richard jumps in to the scrum to save the day. Thanks for the speedy reply.
OS: Win XP Pro
Encryption / Passwords: Disabled
MAC Addresses hard-"tuned" for each computer connecting. Note this worked fine before using the set-up I mentioned below. And this doesn't make any difference if I set or do not set the MAC addy's.
Note this is NOT using the wireless portion of the router. And resetting the router via the IE access workes just as well as unplugging and re-plugging the router...it's just faster to rip the power connection out!
Gone for a few days. Will check when I return. Thanks again for the help.