Jim.
I've been having the same problem as you since I first starting using VE-Pro last year.
I brought it to VSL's attention and Maya from VSL tried to replicate the problem back in November, but although a few emails bounced back and forth nothing was resolved unfortunately.
I'm using the latest VE-Pro update with Logic 9.1.1, OS 10.6.4, a Master MacPro and two slave MacBook Pros. The latency issue occurs both when using the servers on the slaves as well as solely on the MacPro.
Nick