I can't remember the exact setting but in the PCM there is a setting to automatically jump to "Traffic Updates". This will scan other radio stations and if it thinks there is a local traffic update, it will jump to that station. Quite annoying. I disabled traffic updates and this problem went away for me.

 

That is true. Make sure Traffic Programme (TP) is OFF, just in case. However, jumping to a traffic programme station should NOT change the stored station on a preset button.

If later in the day, after the station jumped, you pressed the preset button for that station again, did it jump back to the correct station that is assigned to the button. If it did, it may well be the traffic program issue (a pain in the US where the system isn't used properly)

 

His last post was three years ago, he may no longer have his Porsche. Hopefully he sees your email. If you find out can you post the answer? I don't have that issue, but am curious as to what would cause that.

 

this was happening to me as well. it only happened with 1 certain station, i believe it was 107.9 in philly. after i switched it to a different preset number the issue went away.

 

I had the same problem. Told the dealer when I went in for warranty work, they turned off the traffic program and the stations stay put. No random changing anymore.