DMZ autentication and update problem

Hi, after putting a windows 2003 machine in dmz it seems that it can't find the update from the sophos server.

Port 8192 and 8194 are already opens.

The network is like this:

srv01 dmz ip 10.10.10.10

srv02 sophos and dc server 192.168.1.250 (255.255.255.192)

srv01 resolve srv02 address, but in the log i see the error: impossible find the source for update package.

if i try to reconfigure sophos from the console (right click on srv0, then protect computer) it seems to start, but in the log of the console compare the message attempt to tamper by sophos remote management system blocked.

Any suggests?

Thanks