Bumpmap creates artifacts with displacement

[Kristiffian]

I have a problem when I am rendering this mattress. I am using a displacement map to create the dots in the mattress
and I want to create som additional wrinkles with a bumpmap.

The images attached is with displacement and without displacement.

In the one with displacement there are artifacts all over the mattress.

[rendermax]

I dont see any picture whit displacement and artifacts . . .

[Kristiffian]

I have pushed the bump a little more in this picture.

Do you notice the "web" patterns on the mattress? If you zoom in a littlebit.