Rdp Client goes to Freeze after 10 minute from minimized

Hi,
i have window xp sp2. But this issue i can find also in sp3 and windows 2003
sbs.

If i work in full screen mode and i minizime the window (maybe i must work
on my local pc with local programs) , and wait exactly 10 minutes or more
when i restore before to get connect and work i must wait for about 30, 40
seconds. I view that i'm connect and i view the screen with programs but
before to interact pass this time.

I think is a sort of bandwidth optimization or bandwidth save. But i want
remove this behavior. Because if i receive a call he can't wait 40,50
second to start to work.

My enviroment :

RplClient 6 ( i update to this versione for minimize and automatic restore
issue)
Windows Xp sp2 - Windows XP sp3

I had check in group policy and there is no timeout setting.
I had remove the screensaver.

Can you help me ?