I stand corrected then! Sorry
LOL, it's a problem with the actual chip they used, and the way that the software was programmed. The chip used is an old type of EEPROM ( Electrically Erasable Programmable Read-Only Memory) chip which only has a limited write cycle (meaning that it only has a finite amount of times it can be written to before it breaks down and doesn't work any more). This write cycle is approx 10,000 writes or more.
Then the dingbats at Blaupunkt programmed it a bit wrong.
The EEPROM chip in question is designed to store the volume level when the stereo is turned off, so that when you turn it back on, it comes back to the same volume. Simples. This way, it only gets used infrequently, and the limited write cycle never becomes an issue, as turning the thing of 10,000 times will take a while.
Instead of doing this, what Blaupunkt did was program the system so that EVERY movement of the volume knob meant that the chip was flashed and reprogrammed. That means every single movement. If you turn the volume up 10 notches - 10 flash and rewrites. Think about how many times a week you adjust the volume, et voila, there is the problem.
What they should of done there was write the software to save this data to the stereo's RAM which has an infinitive write cycle, and then store the final volume in the EEPROM chip when the system was turned off.
As you can imagine, the life cycle of the chip in an average A3/S3 was about 3-5 years before the chips started to break down. In Audi Concert head units that haven't been fixed up with a new chip and software, its not if you have this problem. But when.
Well done Blaupunkt.
Not.