Software Instruments suddenly lose volume

Question

I'm using LE8 with the Jam Pack Rhythm Section to do MIDI drums and bass on my album, but as of last week, I started encountering a very weird problem. I'm not doing anything differently with the program than I have done in the past, but now for some reason, the software instruments will suddenly lose all volume at random times. This seems to be somehow related to recording, since it always seems to occur (most inconveniently) when I'm right in the middle of recording a take, and thus I can no longer hear what I'm playing. It doesn't always affect all software instrument tracks. Usually it affect only a few of them or sometimes only the one I'm recording to. Sometimes I can clear up the problem by changing the instrument to something else and then changing it back again. Other times, the only way to fix it is to create a whole new track and drag the MIDI events onto the new track. This is incredibly frustrating and has slowed my productivity down to a crawl, to the point where I'm considering whether I should bite the bullet and convert everything I've done so far into another program. I like Logic-- I just want it to stop flaking out on me!
I've tried playing with the "Independent Monitoring Level" setting, which ostensibly allows setting a different level for record and playback, but that doesn't seem to do anything with software instrument tracks.

Answer 1

Yes, I understand that software instrument regions are MIDI regions. But no MIDI tracks are recorded yet, so there are no existing MIDI events to play back. In this case, the drop-out is happening during the process of recording the first software instrument track in the project. In other words, the monitoring volume on the track that is being recorded will suddenly drop off to nothing as I'm recording, and when this happens, I can't hear the notes I'm playing on my MIDI controller anymore. That was essentially the problem I had with the previous session as well, but for some reason, I was able to make it go away by tying together the overlapping MIDI regions in that session. There are no MIDI regions in this session yet, though, so there's nothing to tie together.
When this drop-out occurs, the faders do not change. Also, the volume of MIDI events that are recorded after the drop-out remains normal. This leads me to believe that the drop-out is not due to some sort of spurious MIDI event. The other key thing is that this doesn't happen every time. More like every other time. If it were a MIDI event, then either the faders or the subsequently recorded MIDI events would reflect the change, but they don't. And again, it is often (but not always) the case that changing the track to a new software instrument and then changing it back clears up the problem.