sorry guys, i forgot to report:
After a conversation with Sequential we found out that the problem is caused by two broken potentiometers.
Sequential sent me two new potentiometers for free - which is very friendly - and detailed instructions on how to replace them. However, some soldering skills are required for this and I'm afraid that you can do a lot wrong on the circuit boards ... and I am currently still looking for a trustworthy electronics repair shop.
Yeah I have also inquired Sequential and here is the reply they gave me:
"For pots that change values on their own, the first thing to try is to turn the pot across its full range of travel 50-100 times. Next, set the pot to its minimum or maximum setting and check whether the value changes on its own. If it does not, set the pot to its midpoint and check again.
if the pot continues to change values on its own after that test, it is an indication that the pot needs to be replaced."
So I did the test and my pot needs to be replaced. Sequential gave me two options:
1. Open up the Rev2, get the panel board out, and send the panel board alone to Sequential. They can swap out the pot and send back the panel board for me.
2. Sequential can send me a new pot. I can either do the soldering myself or find an electronic repair shop to do that. It should be a quick procedure at the shop.
I am currently still waiting for the pot to arrive...