Client Network access Denied

Hi
I have a number of windows 2000 servers running SP4 and CItrix XPe i have MS
office Xp installed on them. I have published Excel and have also published a
desktop to each server how ever on some servers not all when a user launches
excel from the server and when they try to save a document to the Map drive
on there own PC the are not able to acces the client network and it come up
with acces is denied.

the path the users are using is as follows

(excel) file save as->my network places->entire network->client
network->Client

However if the user launches a published desktop to the server they are able
to browse to the location using windows explorer however if the run excel
while in the published desktop the are again denied access to the location
????

any help would be most appreciated