Try formatting your 2gb card with FAT16 (aka FAT).
If this still occurs get an sdhc card that is class 4 or higher.
Class essentially only guarantees write speed, which isn't that important, since you need read speed.
But with higher write speeds you generally get higher read speeds.
I have heard of class 2 cards not being able to handle certain games, but most of those cases could be helped by formatting properly with the Panasonic sd formatter.
But to be certain I'd go for a class 4, they're not that expensive.
2gb mSD cards don't have class ratings btw.