how to use vario tab dispenser

[disney funseeker]

Is there a trick to using the Herma, Vario tab dispenser for the 1000 double sided adhesive?

I can't seem to estimate where to start rolling it so that the tab ends up on the corners of my photos. I end up having to lift the tab off the photo and resticking it.
With this dispenser, I thought the purpose was to avoid having to touch any tabs.

 

[angelmom]

I don't have any problems with mine. I do use my index finger and roll it on the plastic roller to get the tabs to the end of the roller and then on the corners. Good luck!