Hi there,
I have installed your plugin for a couple days and I must say I'm pretty impressed with a the ease of use and the results.
It seems kinda weird though, but while WordPress apparently serves Chrome and IE with cached version of pages, Firefox is served with fresh versions all the time. No Quick Cache html comments at the end of any page and pages load slowly :/ (when logged out, obviously)
You can check it there and tell me if you seem something wrong: http://www.lemellotron.com.
Thanks!
Bertrand.