DECroucher

I'm having trouble getting the RNS-E radio/nav to recognize the SD cards I am trying to load. The manual says it can handle up to 32GB SD cards with MP3 files. Also says they have to be formatted FAT32. I'm trying to use a 4GB Class 6 or an 8GB Class 10. I have done the formatting for FAT 32...complete format (not "quick") and copied the MP3 files. Radio shows "reading" when I insert the card and never does anything else...after 10 minutes of "reading" I eject it. I can test it on my laptop and the files play just fine. I have an older 1GB Class 4 SD card and it reads the files just fine. I contaced Audi Cares and they were useless...simply read me the information from the manual. Any thoughts?