I face a strange problem on a tablet PC. It looks like there's a constant I click lag when I click anything on the screen. If I click somewhere (e.g. stamp) the stamp icon gets selected on the next click only. If I click on the left-right arrows to search for a certain stamp, or change the stamp size, I have to do an additional click somewhere else (e.g. on the bottom area where the stamp description is) to get the right panel changed and see which stamp set is current at the moment.
This behaviour affects the whole software so it's not related to stamps only but it comes up for painting, shape selection or even creating new document or quiting the software.
In Windows itself it does not come up at all, everything works as expected.

OS: Windows 7 Home Premium SP1
TuxPaint for Windows: 0.9.21c
device: HP Slate 500 tablet PC

The OS has all the fixes available from Microsoft, and the latest drivers are also installed from HP.

I tried to find a workaround by modifying settings (e.g. windowed mode, full screen, etc.) but no luck with any of them. The worst was to select 'hide cursor' because the calibration went totally wrong in TuxPaint so I had to force reboot Windows (by holding power switch for 5 seconds) to eliminate TuxPaint make anything to work properly again.

Can anyone help with this?