And you've already confirmed that downgrading to 1.03 makes the problem go away, right?

Certainly sounds like a software issue of some kind to me.

Looks like you will have to either live with the pop, or downgrade to 1.03, until the next software release. There have been a lot of bug fixes since 2.0b3, so it's possible this has been fixed.

Now, if the next software release still has this problem, and if you're sure that downgrading to 1.03 makes the problem go away, definitely let everyone know about it.