I made some squares with the [shape tool] and added shadows. (see attached design.jpg) In those shapes I added text.

While designing, everything looks just fine, but as soon I preview it in IE or FF or build inn browser, the shadow of one of the shapes go astray. (see attached preview.jpg)

I deleted it, make a new one and it stay the same. I deleted it, copy to good one in place of it, but it gives me the same results. If I remove the text out of it, it also stays the same. Only when I move it lower on the screen it will turn "normal".or when I resizing it a couple of times.

What can that be and what can I do?

This probably has to do with your browser size being larger then your Website dimensions. Can you send me a link to the page?

It's a web site still in development Scott, so I don't have a link. I solved it with resizing the object smaller and bag to the intended size.

I previewed it in the internal browser, in FF and IE and it all came out the same. It's no biggy really if you know how to correct it if it happen.