External Effect Using RME Fireface 800

Problem: trying to connect an external effect but having no luck. Anyone able to do this using an RME Fireface 800?
I am using Cubase 7 64-bit on Windows 8.
I can run the VST effects no problem–Direct Monitoring must be turned off to do so.

Thanks in advance.

Specific Cubase version?

Yes.

I’m using external SSL compressor and SPL Vitalizer with RME FF400. On Cubase 6.5 with no problems. With Cubase 7.02 there are some issues. After insert external plugin project is out of sync or no sound. Then must restart Cubase. Waiting for 7.03… ;(

I’ve got 4 external effects units all running successfully through an RME Fireface 800 in Cubase 7.02.

-Rich