I do not know yet if it is a result of the upgrade to firmware 2.0. However my low E string on my JTV-59 has a very buzzy distortion and it distorts in modeling mode or in pickup mode. On a very clean setting any not I play on string 6 buzzes as if it were a bad circuit on all settings.
This guitar does not get a lot of use. I own a Variax 500 and 9 other guitars. This guitar sits in a wall stand in my recording studio most of the time. I already had to send it back once because the G string would only function at half volume. Until I sent it back I had to use workbench to reduce all other strings to 50% volume in order for it to play with balance. It was returned to me and worked just fine.
Last week I upgraded the firmware to 2.0 but only strummed it a few times before placing it back in the wall hanger. Today I picked it up and there is a dominant buzzing on string 6.
I am a bit discouraged as this was not a cheap instrument and it gets very little use. I doubt there is more than a total of 20 hours logged on this instrument although I have had it for over a year.