Yes, my VSTi/DXi synth is checked. I'll try unchecking it tonight. I guess that means no DXI synth but not a big problem as I use realtracks. But surely if one song is working ok, it's not that? Isn't that a global setting? Can it be turned on and off at an individual song level? Anyway, I'll try it tonight.
if you aren't using MIDI tracks, no problem unchecking it. If you DO need to use a soft synth AND send MIDI to external devices, a forum member created a plugin to make that work. I'll see if I can find the thread in which he explained how it works, and post a link to it.
But before I complicate the issue, let's see if unchecking that box helps.