Server licensing

I am getting deeper into the brave new world of thin clients and have a
question about licensing of Symantec AV 10.0.

I understand that with this product I can deploy it on W2003 Server and
administer it out to all the PCs in the place from there, including 2
instances of W2K server.  Each of these takes a license.

I understand that I can also administer it out to our salesrep's laptops,
which connect to the LAN roughly 1 day a week.  Each of these takes a
license.  So far so good.

I am unclear on whether I need a license for thin clients.  This W2003
server is set up with Windows CALs and TS CALs on a per user basis.  Do I
need a Symantec AV license for each user/thin client?  Or just one license
for this W2003 server?  The local reseller says I need one for each and
every user.  I just want to make sure I only pay for what I legally need to
pay for.

Thanks.