I bought this 256 Mb mini Sd card, but instead of having 256 mb memory in it it has only 243 mb so I was wondering what happened to the remaining memory?This is the case with all the mem cards I have whether Sd or MMC, all have different space. I am thinking of buying 1 Gb card and I was thinking if this is the case then I will lose around 50 mb in that card which is a lot.So is there any way to get that memory back?