Did you get this sqaured away and sorted. You didn't mention whicg OSX version you are running. You need the Unversal Audio Driver, not V-Fire specific. If you didn't get this sorted out, let us know. I have my V-Fire working on my Mac just fine, so can walk you though the config and drivers stuff.
Yamaha RM800 (For that good 'ol analog tape feel), Phonic, Presonis and Behringer Pre's AD/DA's. RME: Hammerfall DSP 9652. Every decent piece of DAW software out there but love Ableton and Software Audio Workstation and of course my Roland VS-2480CD + MB-24 and Presonis V-Fire for R-BUS I/O