Another Image Manager thumbnail problem

[sandert]

Hi,

Can someone please help me out with the following problem?

When i upload an image with a filesize greater than appr. 200kb, no thumbnail is created.
When i upload an image with a filesize less than appr. 200kb, a thumbnail will be created.

I've searched the forum for several times but i can't find a sollution.

Regards,

Sander