Not sure you will get much satisfaction with your question on this forum. You might get lucky if someone here used to own a Cougar but you might have better luck here http://keystonerv.org/forums/index.php There are quite a few threads on the Cougar line. Good luck with your issue.
If you google Cougar slide problems you get an unfortunately long list, but try this one: http://www.justanswer.com/rv-motorh...keystone-243rks-polar-pachage-slide-will.html or, if it's new, you may have the problem we had with our Montana. The hole for the slide was cut too small. If that could be the problem call Keystone customer service and get it in to their service center.
Please refrain from posting discussion about SOB even though they belong to Keystone. SOB posting are NOT allowed on this forum. It is a Montana Owners Forum. There are many RV forums out there to help with problems with a SOB. Thank you in advance for your understanding & cooperation.