Try this:
http://www.hpcfactor.com/hcl/
Make sure the PenCentra is connected while running this installer. Once it's installed on the PenCentra, plug in the USB flash drive, and when prompted to type in the driver name, type in
usbclik.
(Make sure it's spelled exactly that way.
) After that, the PenCentra should be able to read any flash drive.
(It'll show up as a folder with an unrecognizable set of characters in "My Handheld PC."
)