Administrator access rights of win 2003 from MAC.

When i connect to the windows 2003 server from Macintosh
using AFP protocol , and then tries to extract one
application , which is .HQX, made in installerVise on
Mac , and residing on the windows server , then ,it
flashes the error message that , the destination disk is
currently locked and u can not extract on the windows
machine .
Instead , it opens the local machine (mac) and wish to
save the extracted file on the Macintosh.
this happens only when u log in to the win2003 server
as "ADMINISTRATOR".
After this i created another user , given the
administrator rights to it ,and did the same above
operations , and , its working fine.
Whats the problem then for the ADMINISTRATOR login , from
MAC ?