No, you are right mate, I don't remember anyone having any trouble with the SD cards. you do know that there are several different versions of Bannerbomb, have you tried another of them? Also, do you have another smaller SD card, possibly in a phone? (a 128, 256MB, perhaps)
I would suggest that any time that I have ever had any trouble with the stage one, it has been a bannerbomb problem, so that is where I would start.