Version:           1.11.2 (using 4.2.2 (KDE 4.2.2), Kubuntu packages)
Compiler:          cc
OS:                Linux (x86_64) release 2.6.28-11-generic

If you have two IMAP servers containing folders which have sub-folders containing mail.  Copying/moving the folders to another IMAP mail server will only copy or move the mail in the currently selected source folder.  All sub-folders will fail to move/copy mail even though their destination folder structure will be created.  The expected behavior would be to copy/move the mail with the folders.  To reproduce create a folder, then create a sub-folder and copy mail to the sub-folder.  Select the parent folder and copy it to another IMAP server.  The mail will not copy, but the folder structure will be created.  I have not tested copying within a single IMAP server.  I came upon this as I was changing service providers, so I needed to move my mail to another mail server.  To my horror I had to copy the mail one folder at a time by selecting the source folder and copying it, then selecting the next one, etc.  Since I have over one hundred mail folders some under sub-folders and some two to three levels deep it took a long time.