wireless connection to WinXP drops

greetings!

here's the scenario:

DSL modem feeds linksys wireless-g router.
network cable runs to a dual boot WinNT/FedoraCore1 box.
a WinXP box is fed by wireless signal to its linksys USB wireless-g
adapter.

i can see internet in all three OS's.
i can feed files between NT and XP.

but....
when attempting to feed files between FC1 and XP, the computers see each
other and the transfer starts, but the wireless adapter loses contact and
locks up (the "link" light becomes solid "ON") within a few seconds of
starting the transfer. this happens in both directions, using both samba
and ftp. if i connect a network cable from the router to the XP box, all
is well.

any clues to why the wireless link is dropping?

thanks in advance!

-p