Question about SD Card....

Question about SD Card
My Camera is Minota Dimage X20.
The SD card is APT 128MB.
I want to buy a bigger card.

The problem is :
The card thickness is 1.4mm, but all the cards on e-bay or store are 2.1mm.
Even the APT card on the net is 2.1mm.

I don't know what's going on,
the slot on my camera doesn't look like can fit in a card thicker that 1.4mm.

Please help me on this.
Thanks.