Having a problem with JTV shut off.  My setup is JTV69/HD500.  At times, after I edit patches manually and I switch to another patch, the Variax shuts off; no lights on guitar, no sound at all.  No response when I change from patch to patch on the HD500.  The only thing that gets me out of this is by unplugging the VDI cable and pluggin it back in.  I dont know if this means anything, but I dont use the battery at all, as I always plug in via the VDI.