VRayLensEffects extremely slow

Hi!

After canceling a rendering with VRayLensEffects applied it takes forever to stop with the message in the render-progress-dialog saying something like “Calculating VRay Lens Effects”. I think I’ve noticed that this only happens if I checked “Low thread priority” but I can’t test it out now because I am in trouble with some projects…

Best regards
Fabian

Noone else having this problem?