Enabling DMZ on SMC router and connectivity problems in suse 9.3

I have been posting about dns and routing and general network dropouts
and connectivity problems. I was finally able to get this problem
resolved by turning off the DMZ on my SMC router (VBR 7004). It turns
out that enabling dmz and providing unrestricted acces to the suse 9.3
host causes periodic network dropouts and poor network performance.
This problem is replicatable at will, but only using suse 9.3. Suse 9.1
worked fine and had no problems, as well as windows.
I had enabled the DMZ and mapped the lan address of the local computer
to the wan address and provided unrestricted access to the internet.
Turning off the same resolved the frequent blackouts in network
connectivity. But now the question is why ? and why only in suse 9.3 ?

TIA,
-A