Hi
I've manged to get it working now. The VST functions ok – it was just that I had bypassed the AU version of the plugin within the same chain, so it was still affecting the stereo image. Once I'd removed the AU version from the plugin chain it worked ok.
You're right about Reaper treating tracks slightly differently in terms of stereo – it doesn't differentiate between stereo and mono tracks (all tracks can be either depending on the source). I think this confuses some plugins – I've noticed that I have to always open Waves plugins as stereo instances (even on mono tracks) in order to get them to work properly in Reaper.
The problem does seem somehow related to Mavericks though, as the AU version was working fine before I upgraded from OS X 10.75. I'd downloaded the latest versions of Omnipressor (2.1.3) after upgrading my OS.
But as I say, all ok now. Just have to go through my projects and save the settings, then reopen in a VST version rather than AU.
Thanks, Tim
