From the JBL website:
"The problem will present itself in one of two ways: Either the unit no longer works or the volume can't be controlled. This condition may occur ONLY if all of the following conditions are present:
1. You dock your iPod® to JBL on stage while both products are on and
2. A significant charge of static electricity transfers from you to the JBL on stage volume control and
3. A specific chip was used in your JBL on stage.
We want to emphasize that there is no safety issue.
We are offering to replace your JBL on stage at no cost to you except for the shipping cost to our warehouse (we will pay return shipping), should you have a JBL on stage with a defective chip. First, let’s find out whether your unit has the defective chip.
Please enter the serial number of your JBL on stage into this field"