Change transparency problems while editing parts

Hi everybody,

As this option works perfectly into an Assembly, it's not working while editing a part...

If I open a part file and change the transparency of any body on it, transparency does not update until I move the rollback bar.

If I edit a part into an assembly I'm not even able to force the transparency updating by moving the rollback bar.

Am I doing something wrong or is it a bug?

Thanks a lot!

SolidworksParts And Features