Problems with CloudFlare CDN

I'm using Wordpress 3.2.1 with Atahualpa 3.6.4.
Recently I installed W3 Total Cache and also enabled the free CDN CloudFlare. It works great but I have a problem with some settings pages in Atahualpa.
I added some css inserts and saved. It worked, but after reloading the page, the inserts disappeared. Sinche CloudFlare caches alla pages in my domain, it also caches admin pages, but I did not have any problem with any other admin page.
I purged the cache and enabled developer's mode in CloudFlare but I could see the changes only a few hours later.
Then I also added the StumbleUpon code to the loop, as I did in the post for the other social sharing sites buttons. It correctly saved and again disappeared after reload. I didn't manage to have it permanently saved.
CloudFlare support didn't manage to solve this problem until now.
Do you know why this happens only for Atahualpa settings pages?