Up until just a few days ago my JMRI and Digitrax PR4 were working perfectly to program my DCC equipped locomotives. Yesterday I added a Digitrax decoder to one of my Atlas GP40's, programmed the decoder using my new DT500 throttle and all went well. I then wanted to add my locomotive to my JMRI roster, using the "Read All Sheets" function and that is when things took a turn for the worse. I plugged my PR4 into my computer, plugged in the PR4 power supply, started JMRI, selected "New Loco" and since I knew the decoder I just choose it from the list and opened the "comprehensive programmer". I then selected "Read All Sheets" and something happened that has never happened before, the locomotive started moving down the programming track at a slow and steady speed. I had to grab the locomotive to keep it from running off the end of the programming track. When I looked at all the CV values on the JMRI sheet, the vast majority of them had the value of 255. What could have gone wrong? Has this happened to anyone else? and if yes, what was the solution to fix this problem? Thank you in advance for any and all help.