Not sure how long it's been by now, but at some point I started having this problem. Any time playing notes from anything in the Instrument or the Patch trees, if the panning for the instrument is centered, it will be almost if not entirely left-panned, as if I'd set it to -42.5 or something. Now, though, the Sample page does it too, when it didn't before. The reverb plays back properly centered, though.
I'm going to try uninstalling then re-installing. Hopefully that will fix it. Okay, that didn't do anything, but interestingly it saved my preferences and previous settings as well as the Recently Opened log. Maybe it has to do with that?
Attached is a screenshot I took after recording from speakers. I played some notes on a center-panned patch that consists only of mono samples.
