SD card adapter wont read new 8gb Memory stik

Hi,

I need help. I just bought a new Sony Handycam DCR-SX44. The lady at Bestbuy said this camcorder only takes Memory Stick's. So I bought an 8 gb memory stick at almost $40. Its a SanDisk Memory Stick Pro Duo 8 gb card.

I have regular SD cards at home (all are about 2gb) I use with my digital camera. Now I tried the slot in the Handycam just to see if a regular SD card would fit and it did! I use a little adapter to plug the memory SD card into to plug into my computer and it reads it just fine.

I tried to put the memory stick pro duo into this SD adapter and plug it into my computer but my computer doesn't seem to recognize it is there.

Is there an adapter I need to buy specifically for this new memory stick? Also, Did I just waste money when in fact it seems as if the Handycam does take these regular SD cards?

Any advice would be great!! Thank you so much in advance.

Melissa