Hi,
Not sure if this is the right place to report bugs for the new OS, but I've noticed some odd behavior from the effects section on my P-6 after updating to OS 1.2.8.b.
First, I noticed that sometimes if I turn off the effects and the turn them back on (on/off button), when I turn them back on they do not work - just dry signal. This seems to happen kind of at random and not all the time.
Second, last night when I turned on my synth, I was getting some really weird behavior from the effects. If I had one effect on, the sound was fine with the effect working properly. However if I tried to add a second effect, they seemed to cancel each other out and the result was a muddy dry sound. This happened over all of the effects and no matter whether I was adding effect A to effect B or vice versa. Additionally, as I was scanning through some of my patches, I noticed that Flanger 2 was acting really strangely with some unpleasant phasing sounds.
I shut down the synth and restarted it, and everything went back to normal after that.
The new OS is awesome!! Just wanted to report these oddities.
(By the way, I should note that I was one of the users who experienced the synth stopping at 1 during the update and not rebooting. I restarted, and everything seems to run smoothly.)