VS-20 - Unable to read/write data

I have installed VS-20 on W7 64bit twice and continue to get this message when I open the Editor.
Also, I try regardless to define Midi I/O devices but, when I Apply/OK the dialog, it insists that I haven't defined any.
I have tried USB sockets at the back and on the front of my PC.
I have a Saffire Pro 40 connected vi FireWire already - is this the problem?
Has anyone any experience or ideas how to get the VS-20 working so that I can get my hands on the great guitar effects to use with my X3e Producer DAW.
Thanks to all in advance

Thanks Wookiee.
I suspected that it was the multiple ASIO drivers thing.
To access the COSM effects in the VS-20, I have installed its driver and the editor on a laptop and taken the output from the VS-20 into my Saffire interface to my main PC where Sonar is.
This way, the signal goes from my guitar through the VS-20 on the laptop and out into Sonar on the PC.
I can also use this setup, with/without COSM, through the VS-20 line-in, for the output from my GR-30 guitar synth.
The connections remain alongside each other on the VS-20 so all I have to do is push a button to switch between the guitar and line inputs on the VS-20 without having to swap or use additional inputs at the Saffire end.
A roundabout configuration but seriously effective.
Of course, this means I cannot use the VS-20 as a DAW controller for Sonar on my PC but that does not bother me.