Thanks for the response Michael, and i did understand you perfectly, the steps i performed were, as you say, pretty much the same as flushing the cache, however, after doing this and confirming normal view i raised the Cache TTL above the 3600 (3 times the amount) that it was set to made no changes to my forum an hour or so later checked the logged out view and again all CSS was missing. I now have it set to 3600 so the most time that a person will see the forum without the CSS will be one hour.