How to shrink parition in Eee PC 900

To my surprise, I found that I CANNOT use Disk Director 1o to shrink my one and the only one partition. Every time I tried it, the system rebooted, and then it will be back to normal.

Luckily, I have TrueImage 1o. So I use the partition I backuped a while ago, restore it WITH resizing of the partition, and finally I got a shrinked partition.