Problems recording host automation with 32bit bitbridged plugs, of which I still have a few.
Also MIDI out problems, so with the likes of Realguitar you can enable midi out on the softsynth, and output that
to another instrument. Use the realguitar's pattern generator to double a guitar from another library etc.
Of course, now Musiclab has a 64 bit version so it's no longer a problem.
Doesn't work with bitbridge, both recording host automation and softsynth Midi-out seem to work fine using
jbridge on all the vsts I tried.
All those IK MM ones are all still 32 bit (last I checked anyway).
Slowly moving to 64 bit :-)
Cheers - Cliff