The url for your css is giving an error:
Paste this in the browser and you will see the error page:
http://www.octomino.com/Data/Sites/1/skins/styleshout-techmania/csshandler.ashx?skin=styleshout-techmania&config=style.config&add=
I would look in the error log under (key icon) Administration Menu > System Log or download the file /Data/currentlog.config, only the last error at the bottom is of interest so please don't post a lot of your log if you decide to post it, just the last one at the bottom.
In IIS 7 the default application pool is "Integrated" which is new in IIS 7, but you need "Classic" so look around in your web control panel for an option like that or ask your host if its available.
Hope it helps,
Joe