So this just started happening last night but apparently if I just unplug my iPhone 4 from its dock on the Audi MMI while the music is playing, my home button becomes disabled and I can't exit an app once I launch it. The only way would be to hold the power button and restart the entire phone. I didn't realize this was linked to the Audi MMI until this morning when I plugged it in again on my way to the Apple store to get my phone looked at when everything went back to normal once I docked my phone. Through some trial and error, the only way to keep this from happening is to switch to Radio or some other non-iPhone related task on the MMI before i undock my phone and then everything is fine. This is annoying and I don't know if its the Audi MMI or my phone that's acting up. Anyone experience this as well? I have a Audi Q5 2010 fwiw.