vray material and opacity/shadows

[powerandrubber]

I've been having a problem with vray material and shadows. As you can see a standard material with opacity produces a correct transparent shadow. A vray material with grey in the refract slot and IOR set to 1 produces a solid shadow. Any way to get a correct shadow with a transparent vray material?

[Sushidelic]

just check "affect shadows" in the vray material.

[powerandrubber]

Thank you much!