Some background, I'm an air traffic controller and I bought my '07 E90 sedan in Feb of that year when I was living 5 min from an AF Base in CO. I moved back to Canada in the summer of '08 and again live 5 min from an AF Base. I've never had an issue with the stereo until a few weeks ago when I started getting the "alarm" message and the aux would switch to radio on its own. I think that can rule out any airport interference as nothing has changed WRT transmissions or radio interference from the airport in that time.
I've tried the fixes mentioned and nothing seems to work (turned off RDS, switched to European region) Hope this helps the trouble shooters as this sure is annoying
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