Outlook Express address book error

Outlook Express has a problem wich cost me an hour of my life. I document it here to the aid of others. (I did search in the knowledgebase on MSDN or support att Microsoft to enter my newfound intel but there was no good place. MSDN which some years ago was a good place to find information has IMHO deteriorated.)

Problem: Outlook Express refused to open the emails. The error information was something like "An error has occurred." but in swedish so it was useless for googling.
Opening the Address book there was a better error message "The Address book cannot be opened." but likewise in swedish. Slightly narrower error message which helped me a lot.

I fixed the Wab (address book) file by copying the automatic backup (myusername.wa~).
But OE still complained about a corrupt WAB file.

Googling did little to help so I rebooted "just because". And it worked.

To make OE read the address book again one has to reboot the computer. (Technically it might be enough to zap exactly the right process or do some registry hack but I don't know which.)

Lessons learned:
1) When localizing a product - make each error message searchable. Either by a unique ID to search for or by letting the user see the international (english) text besides the local.
2) Give the user a sporting chance to track the error. If it is not possible to give a proper error message - describe where to find it, like in a log file or something.