FPS200 USB fingerprint sensor driver

Hello

I need some help.. The driver was compiled without errors and seems to run correctly.. But when I try to capture a fingerprint, it hangs and looks like this:
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./capture tst.pgm
Number of Frames: 1
Destination File Name: tst.pgm
Source Device: /dev/fps200

Dimension: x=0 y=0 width=256 height=300

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ctrl+c exits the program, but the tst.pgm is 0 byte.

I use gentoo linux 2.4.28-r9 with gcc 3.3.5 but also tried with linux-2.4.18 and gcc 2.95.3 on another pc. Usb support of course is enabled (kernel)

i have veridicoms 5th sence usb peripherial device, which uses the fps200 sensor. Under Windows the device runs correctly.

Any Ideas how to fix this? Maybe it's a problem with finger detection? This device has got a lid over the sensor whichyou have to push away while putting the finger on it. (see http://www.securenetsol.com/catalog/images/ver5thsense.gif)

By the way: "cat /dev/fps200" gives no output at all, is that correct?

thank you for any suggestions