Problem of USB drive not found on Device Manager - Vista related

Hi everyone,

I need advice:

Version: Vista Home Premium, comes with ACER Aspire notebook series.
USB Drive: Lacie, 40GB in size. It's formatted as FAT32 and divided into 2 partition.

Both partition can be seen on Win XP (I have another laptop to check) and fully used, but one of it cannot be seen on Vista. Using Disk Manager to try to check and enable it, it keeps saying error saying that Disk Manager is not updated, try to refresh, etc.(unfortunately, I forgot the exact error). I tried the step instructed by the error, but result is the same. This partition can be seen as exist on Disk Manager, and similarly the other one., however, the drive letter and content cannot be viewed.

I have tried copying out the content and formatting the drive again, but same result.

Any idea to fix the Vista other than re-install the whole O/S?