Cookies, and more cookies

I'm currently working woth an application is servlet based and is using cookies and has done so with out any problem. Just recently I have discovered a problem where cookies from one particular page of this application are not being written to the web browser. I have checked the data in the cookies, URL encoded them, and there isn't any exception thrown when adding them to the response. But the cookie is just not getting written. Any one have any ideas on why or where I can look to try and figure this one out? I'm stumped....