Unable to fetch item from backend (collection 15, resource -1)

[cmrntnnr at gmail.com]

Several folders from a recent archive import return the following popup 
error message:

Unable to fetch item from backend (collection 15, resource -1)

The mail in the affected folders is visible/accessible.

The folders do appear to contain mail as kmail reports a significant size 
to the contents.  The original archive was generated by kmail from kde 
4.8.4 on opensuse 12.1.  The error is generated by kde 4.9.1 on 
opensuse 12.2.  Adjustment of folder properties and subscriptions does 
not give access to mail in the folder.