Playback errors after pause
I have the same problem. I don't think it's channel dependent. It seems to lose its position and jump back to some sort of checkpoint. Occurs when jumping forward, not when jumping back. I also notice that when jumping forward, the cursor visible at the bottom of the screen goes back and then forwards. There seems to be a minimum length of pause after which this starts happening, perhaps 20 or 30 minutes, so if you pause for five minutes then it won't happen.
The 360, like the V6, has a rolling timeshift video buffer for the last ~90 minutes which is stored locally. The negative numbers such as -37 and -1:14 are the offset from live, so ‑37 = 37 minutes behind live and ‑49 = 49 minutes behind live. When you pause live TV the box remembers where “live” is and skipping forward moves you towards live with the counter counting up until you reach 0 (live).
The works really well on the V6 but not always on the 360 because box is losing track of where "live" really is. This is caused by the timeline logic (what’s live, where you paused, how far behind you are) being partly server-driven and when the cloud session metadata is out of sync you see the problems you have reported.
This problem is never going to be fixed IMHO as it's annoying but hardly a showstopper and, crucially, the 360 is now a transitional product with Stream already the primary/sole box for new customers. The 360 will be VM's last set-top box.