I’m using OpenSUSE 12.1 with kde4.8.2 and since several days the mail messages are without bodies. I use Imap to access my accounts. Accessing my accounts via web-interface shows regular messages, when these accounts are then accessed with Kmail the result is missing bodies both in Kmail and mail-server. Akonadi is active.
Hope someone can help
The reason for this is a bug. In your case it could be a regression, because it should have been fixed with the currenty 4.8.2 update.
https://bugs.kde.org/289287
If you can reproduce this, it could be worth to write a bugreport to the openSUSE bugzilla and to seek help there because this should not be the case anymore.