The SPID has disappeared finally. I use Hyperbac on this server. I tried stopping the Hyperbac service but it did not respond normally. So I opened up Task Manager and killed the Hyperbac processes that were running. Moments later the backup SPID

finally went away. So it appears there was some hangup between SQL and Hyperbac.

I restarted the Hyperbac service. ....now we'll see what happens tonight.