Hi there! I have the same reseting problem with my POD HD500X. I have identified the actions that lead to it: To hit switches FS5 to FS8 (any speed, any sequence), ONLY if they are used as A B C & D function, about 36 to 40 times (normally 36).
I thing this is some buffer flood (or something like that) problem.
I live in Brazil and there is no Oficial Technical Assistance here capable to repair it. Anyone knows if I can send this information do Line 6 to try changing any memory or CHIP here in Brazil? Would they help me with that? I have already flashed the latest version, with the option "erase my presets" set. I have already reset it manually (power on, arrow left pressing). No lucky at all.
I would appreciate any help. I have made a video showing the problem. If it is ok I can put the link here (youtube or dropbox, if any is allowed).
PS: I have (second hand) bought it a few months ago and I have had no time to configure and use it. I started to use it last week and noticed the problem. Last night it has reset some times during a live gig... About 6 seconds with no guitar sound each time... Just when I was starting to love my POD... :-( Today I did a lot of research here in this forum and the net, and a lot os tests, until I discovered what leads mine do reset. Very best for you all!