Buses not responding

Safe to ignore, would delete if possible. If anyone's interested, here's my travails of the past hour. Solution: Close and re-open SONAR. Sheesh.
 
 
I have 5 tracks outputting to a bus which has a volume envelope on it. The bus' envelope been working all along, but all of a sudden it stopped working. I've laid out my troubleshooting steps in detail here, but for the short version, skip to step 11 below.
 
1. Corrupt bus? I created a new bus, put a volume envelope on it, and re-routed the tracks to that instead. Still nothing. 
2. Track problem? I created a brand new track, copied clips into it, and sent it to the new bus. Nothing.
3. Something wrong with the clips? I removed the copied clips and copied clips from a completely different track to my test track. Nothing.
4. Does ANY envelope work on the bus? I added a reverb effect and reverb envelope to the bus. It works. Volume envelope still does not, however.
5. What about pan? Removed the reverb effect and envelope, added a pan output envelope. It also does not work.
7. Some effect messing things up? Bypassed all effects. Still nothing.
8. Can I get this test track to respond to volume and pan envelopes at all? Added envelopes to the test track itself, they work fine.
9. Is the entire bus envelope mechanism failing across the board? There are half a dozen buses, but only one that has envelopes on it. I added volume and then pan envelopes to a different bus and soloed a track that routes to it. Also does not work. Apparently NO bus envelopes are working for volume or pan, but do work for effects. 
10. Wait, is it not envelope-related at all? Do the regular bus controls work? Soloed a completely different track routing to a completely different bus. Moved the bus sliders during playback. NOTHING! 
11. Does my song have any of my carefully crafted levels still in there? I un-soloed everything and played song back as normal. All volume and pan settings are being ignored, except those on the tracks themselves. No bus routing is working, unless those buses have effects on them. Project is completely f**ked at this point.
 
What have I done recently? I am doing final mixing today. I've adjusted a couple envelopes (in the tracks themselves) on unrelated tracks. I changed panning and volume on a couple of the tracks that output to this bus, and changed one track's interleave to stereo. (I had run into a DirectShow error which was resolved by changing the interleave.) I changed a little EQ and moved an Exciter dial.  
 
Ideas?