I'm not familiar with a version 5 decoder. However, you can easily try turning off the 'acknowledgment' that interferes with double CV changes. Try POM --> CV62 = 0 . Then try running the JMRI Decoder Pro.
In any case, you are missing out on a heckuva lot of fun. Personally, I'd swap the decoder for a Titan and see what a real high end decoder can do. :-)