Not sure mine is the same issue, but I will chime in anyway and see.
We have a 625 and a 722. The 722 has been fine for the past 3 days. 625 has has a problem with Program Guide Downloading (when it is turned on, it shows the downloading screen). Have NOT had to reboot (receiver is in another room so not convenient to reboot), but just cancelling the Download Screen, has allowed TV to be watched.
As for the timers, I didn't turn my tv on this morning (busy day) until I checked for this thread, and the Download Screen was on. However, the 2 timers I have set to run everyday were recording (one was in process, so I don't want to mess right now).
As for it being software related, I don't know that it is as the 625 with the problem has software version L5.31 (Complete Line Says - L531GJ3D-N).
Hope that helps,
Geoff