CSS optimization makes Imageflow display weirdly.

I'm having problems with Imageflow when optimizing the CSS files for my site. Removing the @utf8 and @media screen, projection { } bit solves the vertical images, but another problem appeared. The images now gets calculated differently which makes them grow and be positioned outside of the container.

An example for the front image:

Without CSS optimization:

<img width="470" height="325" src="http://www.perrong.se/files/img4.png?1274435644" alt="" class="imagefield imagefield-field_portfolio_img" longdesc="/node/51" style="cursor: pointer; display: block; left: 282.903px; height: 288.849px; width: 417.72px; top: 12.4342px; visibility: visible; z-index: 10;">

With CSS optimization, causing the image to not be centered and other images to be placed outside of the container div:

<img width="470" height="325" src="http://www.perrong.se/files/img4.png?1274435644" alt="" class="imagefield imagefield-field_portfolio_img" longdesc="/node/51" style="cursor: pointer; display: block; left: 347.277px; height: 354.576px; width: 512.772px; top: 15.6157px; visibility: visible; z-index: 10;">

Has anyone else experienced this problem, and perhaps found the cause?