PSP - USB Device Not Recognized

Luck run out of me... just really can't figure out what's wrong with the set-up. It should have been plug and play as with all other USB devices I connect with my PC... How come my PSP can't be recognized by my OS and considered it as "Unknown Device"? I've tried it with anumber of other computer and the PSP was recognized and had been installed.

I read the PSP manual again particularly the "Troubleshooting Section" and found out that a PC may not recognize the PSP system and/or the Memory Stick Duo connected through a USB cable when using a USB hub or other devices. The manual states no other instances when the PSP system may not be recognized by the PC. I assume that the fact that my PC's USB ports are available through a PCI expansion slot is not an issue here.

Does anybody out there who can help me with this? Please....

For your reference:
Pentium III 550 MHz, 256 Mb memory, OS XP SP2
Mother board originally no USB ports built-in, used PCI expansion slot to mount iNTEX 4 port USB card (USB 2.0)

Thank you very much for your time.