Two things come to mind....

1) I know you have the latest firmware, but it sometimes helps to reflash the memory in safe mode. If you haven't done this already, power up the X3 while holding down the right navigation key. Then use Monkey to 'Flash Memory'. Make sure you back up your tone bundle before you do this.

2) There are somtimes problems with the chrome knobs (pots); they can somehow be perceived as moving by the X3 even when they're not; the slightest vibration can do this. This can trigger both the asterisk and the weird noises (because suddenly an effect/volume can seem to suddenly be dialed to nearly max). Try 'parking' the knobs - put them at the 0% or 100% position before turning the X3 on. This is apparently a  kind of dead zone for the X3 and it will no longer see them as moving.

Does this problem only happen when you use the Variax input? If it does, you might just need to replace your Variax cable. I had a similar problem where the X3L would keep restarting. I swapped the Variax cable for a spare that I had and the problem went away (always a good idea to have a spare Variax cable).