OGM Nav Attenuating iPod Volume

[parshal]

I had been noticing that the volume on my iPod gets attenuated at times. I'll be jamming fairly loud and it drops a bit. I raise the volume about five points and it's back to the same level. I thought my amp was overheating. Tonight I noticed the volume drops when I start the nav. Once the progress bar get to about 50% it drops. As soon as I press the exit button and hit yes to exit the volume returns. It does not drop the volume if I'm listening to XM. It only happens with the iPod.

 

Any else have this?

[Bluegrasseddy]

I have had variations of the same problem.