I've seen high dollar pre/pro's do the same thing. I wouldn't worry about it unless it begins to “freak” out on a regular basis. My Integra DTR 7.4 did this last year when I was fiddling around with the settings on DVD player I guess it wasn't happy with the adjustment I made... Very weird.

M80's VP150 QS8's Earthquake SuperNova MKV-15
Integra DTR-7.4 Outlaw 755 Outlaw M200's Outlaw ICBM