Scan disk 4 Gig chip..

Hello,

My phone wants to format the chip so I did.. then I put it in a USB connection and on the computer it says ANY file is to big to put on the chip.. nothing on it. So I format it again on the computer and it will take the file.. then i put the chip in the phone and the phone wants to format the chip.. again.. ?? but with a 1 Gig chip it works fine... ??? Why??