problem writing to USB 2.0 hard drive

[agent64]

Hi,

just bought a USB 2.0 card and USB 2.0 external enclosure. I installed a hard drive in the external enclosure. I have no problems at all when reading off the hard drive but when writing to it it's VERY SLOW. It's almost as if it works in USB 2.0 speeds when reading from the hard drive but in USB 1.1 speed when writing to it. Please help! Thanx

Windows XP Pro *all updates installed*
Epox 8kha+ mobo *latest bios*
512 MB RAM
Maxtor 20 gb hd
Maxtor 30 gb hd
Linksys NIC
MS intellimouse optical USB
SB Live value *latest drivers*
Athlon XP 1900+
GeForce 2 GTS *latest drivers*
Syba USB 2.0 PCI card (NEC USB 2.0 chipset)
ME-320 3.5/5.25" external enclosure (maxtor 80 GB hd)

Thanx