I've read all 19 pages of this topic, so I'll apologize up front if I missed a discussion of my particular problem.
I installed 2.0, and the installation seemed to have been accomplished. Monkey reported that 2.0 was in the system. Workbench HD seemed to tell me the same. However, I could not get my JTV69 (non US) to send a signal to my amp. (When I turned off the Variax function, the "straight" sound of the guitar came out of the amp as usual.) I restored 1.9 to my Variax and, presto, the various models sounded through the amp. Hopefully, there is some simple step I missed after installing 2.0 that prevented these models from getting amplified.
Thanks in advance for any help.