VST tempo sync on slave-system

Hi there

Discription of system:
a quadcore win7-64 with cubase pro8 , RME DIGI96/52
an athlon winXP-SP3 with VST host i.c. Nuendo 3.2, RME PAD/8
audio connected by ADAT
midi connected by “Copperlan” on LAN

I cannot achieve tempo sync for the VST plugs on the slave-system.
That is , not with Steinberg hosts like Nuendo, Cubase SX or V-Stack.
However, Reason 3.0 wil have the instruments synced.

So , what is happening?? or rather , what is not happening??

Thnx in advance for your replies Larenzo