Thank you for your hints.
@deej: I downloaded and installed the M$ vc++ redistributable package - but it didn’t change anything.
Then I just copied the 2 dlls to the system23 folder and then it worked fine!
So I now can use the Beta 2.0 version. 
I’ve also got a new lens that is brighter/faster - I don’t know the english term 
- well it sees more light and my blobs are much brighter.
Now I have the problem that the camera also sees the ir-light from the LEDs at the edges of my screen and this light flickers, so it is not subtracted well.
I have also changed my config.xml file as suggested:
<filtergraph>
<dsvlcapture label="dsvlcapture0" />
<mono label="mono1" />
<smooth label="smooth2" />
<backgroundremove label="backgroundremove3">
<threshold value="0" />
</backgroundremove>
<simplehighpass label="shp5">
<blur value="197" />
<noise value="3" />
<noiseMethod value="1" />
</simplehighpass>
<scaler label="sc6">
<level value="105" />
</scaler>
<rectify label="rectify7">
<level value="23" />
</rectify>
</filtergraph>
I have attached a new screenshot, where you can see my problem. When I turn down the scaler-level or the rectify-level, then the LED-flickers vanish, but the touch blobs start to flickr. I can’t find a good balance. Do you have any hints?
One idea I have is to put the cam nearer to the screen to get a smaller vision area, but this would result in a smaller projection and I would rather find another solution to make my screen more stable…
PS: The lights you see at the edges a about 6 cm from the actual acryl plate edges away.
Click thumbnail to see full-size image
)
