Transcend 4GB 150x SD cards

[coach_ng]

Is there any reason why 2, what seem to be identical cards, report slightly different capacities?

My original 4GB 150X card reports 3.86GB and the new one is 3.83GB.

I have purchased them about a year apart and the only noticeable difference is that the new one does not have the trademark TM beside the SD logo.

On my Pentax k10d 10MP DSLR it's a difference of 2 images and on my Canon SD400 (5MP) it's a loss of 13 images.

Am I just being too anal? I guess I'm just upset that I felt that I was almost ripped off with what looked like ti might be a fake.