May be relevant to this thread...I recently acquired an HX effects, and love it so far. I had 2 odd behaviors after updating to 2.71 immediately after unboxing (it was loaded with 2.50). I put the init into analog bypass, and got no sound at all, on any patch. Couldn't toggle back out of analog bypass. The only thing that fixed that was reinstall the firmware. But the problem that persists is the all four patches in bank 15 have no sound at all...no effected sound, and no guitar-only sound....nothing at all. All other factory presets are fine. I've tried other firmware versions, and have reinstalled 2.71 again...same problem with all. Suggestions?