I've noticed some firmware problems with my newly acquired JTV89. When I got the guitar, the very fist thing I did was to put the battery to charge and plug it via VDI into my HD500. It sounded very nice, the models were very realistic and alive.
Ok, so I go about updating it to 1.82 (it was set to 1.70). After the update, some models just sounded weird. The Les Paul bridge sound like an out-of-phase middle position (just on the 3 lower strings), the Strat lost ist sparkle and the 12 strings are not tracking as quickly as before, you can hear the strings "sliding" to pitch.

So I try reflashing, rolling back to 1.70, back again to 1.82 and guess what? Every time something sounds different. There doesn't seem to be any consistency between all the reflashes and updates, something always get fixed while another thing gets messed up...

Another problem: when I edit a model in Workbench. Let's take the Spank for example. The model from the guitar sounds nice and sparkly, but if I so much as touch Workbench, it instantly sounds darker and lifeless, like the old Variax500 I had a while back. Also, saving ANY of the JTV models to disk and editing them makes them sound like the older variaxes, even though Workbench labels them "Tyler Variax Model". I've notced the file extension is the same for TJV and 500/700 guitars, so is it possible that the stock models in the JTV are "converted" to 500/700 models as soon as you edit them in Workbench? It is really annoying, because if I just need to adjust something simples like pot values or the capacitor, the models loses all its authenticity..

Anyone has some insights?

P.S.: quick test to exemplify the problem: I take the Spank 5 model and copy it on top of Spank 4, so now I have two Spank5 side by side and they sound the same. Then i take one and edit it in Worbench (change the capacitor to 11uF than back 47uF, so no change after all). The two models now sound completely different, the edited one being darker and less sparkly, just very plastic.