Best way to plug virus ti in..?

[IamEvil]

I have a bit of a confusing set up at the moment and need to sort it out for the best sound quality and stability...

Currently I have my virus ti connected to the pc via usb but not as my main soundcard..

My main card is an Edirol M16DX usb mixer to which the virus connects to via SPDIF.

I also have an Emu 0404 pci which Ive recently removed.

Because the virus and the edirol are both connected together via spdif and to the pc via usb they seem to want to fight over who has the master clock and it is causing the mixer to mute and making me have to fiddle a bit when I switch the gear on.

Im thinking about scrapping the setup and trying a different way , do you think I should..

A) Use the Edirol as a mixer and not as a soundcard. Have it output its mixdown channels to the virus SPDIF input and use the virus as the main soundcard

B) disconnect the virus's pc audio (can I do this and still control the synth via usb midi?).
Connect the virus to the Edirol mixer via analogue outputs and use the Edirol via its usb as a 16 input soundcard.

C) Plug the Emu 0404 pci back in the pc (slightly better latency), use the edirol as one would use an analogue mixer and the virus as any normal synth via midi/analogue outs.

cheers ..