I am having quite a serious problem with Quick Cache. Apparently, it is caching the pages on my site with the admin-bar visible. This means the last user to generate the cache will have his or her admin-bar visible in the cache that every visitor sees!
The reason I know it is a problem with Quick Cache is that clearing the cache and launching the site with my profile (where the admin-bar is disabled) "fixes" the issue.
Although this is not a security issue it is incredibly confusing for my users. I would very much like to see a fix for this.