Today, i was playing my POD HD400 and shut it off for 5 minutes. When I came back and powered it up it defaulted to Bank 00D "User". There is no sound. The Mode switch light is off and none of the FX switches or AMP switch and lights will work. The Up/Down switches, the Preset Switch, Navigation button, Amp rotary selector, and all Pots work. The TAP switch and the Tuner do work. The problem seems to be with the lower row of stomp buttons, except TAP. All the other banks say "User" and there are no FX settings stored. I have tried turning off the power for 30 minutes and re-starting several times. I have not used a computer with this POD for over a year, since I left my company and had to turn that computer in. I have not installed the Line 6 software on any of my other computers. This unit was only used and stored in my house for over 3 years, and has only been taken away to practice about 8 times, all in this year. It has had no rough treatment whatsoever. The first one I bought failed within 2 months, and I took it back and exchanged it on a 2 year in-store warranty. I have had no previous trouble with this replacement unit. I would appreciate any advice from forum members. Thank you. .