I just saw that the current build for VMSpc is build 4 rather than the build 2 I have installed. I have an older serial jib using the prolific driver for the usb connection to my W7 64 bit pc. I am not having any issues with my current installation and would like to know what advantages does b4 have over b2 and should I upgrade or stay with what works? Bernie Dobrin 2002 Travel Supreme Cummins ISL 400