Page layout corrupted after uninstalling CKEditor

My site was ok but when I uninstalled the CKEditor module something happened to my theme and to css.
I use a Zen subtheme with a two columns layout. The content area is now expanded and goes under the sidebar on the right; a menu (Nice Menu) on the header area is partially beyond the page limit; css classes set if Panel regions/rows/columns (for certain pages) seem disappeared.

I uninstalled also the two modules under the uninstall tab (Admin > Modules > Uninstall), but it didn't solve the problem.

To be sure that the problem was on CKEditor I tried to restore a previously saved version of my site (restoring the entire database); then I only uninstalled the CKEditor module and the problem appeared again.