Only the first partition can been seen and accessed under windows after my flahdisk has been partitioned with fdisk

I now have a problem seeing and accessing some partitions on my flash disk after it has been repartitioned with the fdisk utility under the Debian Linux. I repartitioned my 16GB flash disk into two primary partitions with one being 4GiB in size and the other one taking the rest of the available space. I wrote the changes to the disk using fdisk with root privileges and formatted the two partitions with "mkfs -t ntfs" command. The two partitions can be mounted and written to under the same Debian OS with which they were formatted, but when I plug the flash disk into another PC with windows 7, only the first 4G partition can been seen and used(there is only one icon for the partition in My Computer when it's supposed to show two icons) with the other partition never popped up. When I try to identify the disk in the System Management Panel, I can see the two partitions and only the first 4G one was assigned a disk label.

I tried to repartition the disk again with one primary NTFS partition and other numbers of logical partitions. The problem persists. What seems to be the problem? Thanks for your advice.