how to exclude posts under specific category?

Do u mean specific posts can appear later under a category or do you mean simply posts which happen to appear under a category currently. If its the latter you can simply just exclude the name of the post. If its the former then you might want to try the more advanced and less buggy w3tc-fixed version which is well ahead of 0.9.5.4 in terms of features (e.g. exclude by category, meta keywords, author, etc), security, and bug fixes.