The same happened to me this weekend, and it has happened a couple of times before. This time though I did have the latest firmware on my JTV89F, HD500X Considering I gig several times a month with this setup, the erratic display happens only very rarely, but I can't seem to reproduce this. This weekend though I was playing at the brides walk in at my friend's wedding, and when it happened I was under a lot of pressure. I power cycled everything, and then reconnected, but still the HD500x was showing the knobs, and not the patch. In the end I disconnected the Link cable, which ectified the display, and went via analog out from the HD500x to the DT25. The next day however, at another gig, it all worked fine, though from now on I will always keep a jack to jack ready to connect with, just in case.