@ dvb
I don't encounter any problem with fat filesystem (with or without swap partitions).
But I agree for "multiple partitions": today I noticed that, if there's only one partition (fat or ext doesn't matter), it's mounted on /media/mmc1 also after a usb connection. But if there are multiple partitions on sd card and the first one is an ext filesystem then /media/mmc1p1 is created after that usb cable is disconnected.