The program seems not to be able to use the Virtualstore, and therefore the program needs to ask for permission every time as it primarily writes files in no-no locations for UAC. To circumvent this problem D-Link is not actively checking UAC status and failing the program (stopping) whing it is on.
No explanation from D-Link, so this is one I have to live with. My work-around is to run D-ViewCam within a VMWare Virtual environment in which UAC is off. Drawback: performance is a little lower, but still acceptable.
Just my $0.02