SP4: HTML Container Cache: removing a user from a group does not flush his skeleton

I have two groups: Editors (RW) and Publishers (RWA) on the home page of my site. I put all the pages of my stie both in edit and live mode in the HTML cache.

I then added a new user and subscribed it to one of the group. Ok, he could reuse the HTML cache entries from such a group without having to reload all the pages from the DB.

Finally I removed such a user from my group (so he has no more acces son the site). He could still see all the headers with the tab to enter in edit mode on all the cached pages.