Compass is very slow

Hi,

I tried the Compass sample Code of Extensions/example.php, but it is extreme slow, when you import the complete compass project.
It takes about one minute just to render the small example.scss file. So it would never work for me with a real project.
If I just import one mixin like `compass/css3/border-radius` it's faster. Not that fast like using the parser without compass, but it is better.
