fprint_demo just hangs.

[THEcreationist]

I have HP Pavillion dv 2700 laptop having a AES 2501 fingerprint reader. I have installed all necessary packages along with fprint_demo on Fedora 14 i686. When I issue the command fprint_demo, the gui of fprint_demo opens.
It says:
Device ready for use.
Driver: aes2501
Imaging Device.

Now I select one of the fingers form the given list to enroll. A dialog box appears prompting to scan the finger. But, whatever I do, it just hangs for long time, until I forcibly quit it.

This thing happens with every Linux system I use (Fedora 12, 13, 14 and Ubuntu 10.04). However, the fingerprint scanner worked fine on Fedora 12 around 3 months ago, but not now.
However, it works without problem on Windows 7.

Please help.