the Internet Options tweaks that Don recommended did not rectify the
problem that i was having (thanks just the same Don!). however we did
have some success using another approach. by using the "net use"
command you can specify the user credentials, and override the cached
for example at the command prompt:
net use x: \\server1.domain\share1 /user
you will prompted for a password and it will map your local x: drive
to the remote share. thereafter, any requests for shares on that
server will use the defined credentials that you specified in the net
hope that helps somebody else.