I received my Pandora today and initially had a problem with the right hand SD slot with one of my SD cards. My 8Gb Lexar SD card worked fine in both SD slots, but my 16Gb Kingston SD card jammed in the right hand slot the first time I inserted it. Repeatedly pushing the card in didn't release it, but I managed to release it by pushing the card up and in with my thumbnail. The 2nd and 3rd time I inserted the 16Gb card it still jammed and had to be released by pushing up and in, but subsequent insertions have ejected normally.
As I was at work, I measured the maximum thickness of both cards with a micrometer,
8Gb Lexar - 2.09 mm thick
16Gb Kingston - 2.21 mm thick
Looking at the SD card specs (wikipedia) the nominal thickness is 2.1 mm, which suggest the 16Gb SD card is out of spec, but I don't know what tolerance is allowed.
Hope this is of use and makes sense, its been a long day.