ERROR : Could not complete request. Query: CREATE "Sent Items"

If this error message fills your entire folder column in squirrelmail, you probably have set 2 conflicting options. The conflicting options which will cause this error are located in the Folder Display options page and the options are :
 * Sent Folder : [Do Not Use]
 * Show Variable Sent Folder : Always

To fix, select "sent folder" to use, or disable the Show Variable Sent Folder.