Meta Data Services Programming
Restrictions for Microsoft Jet Repository Databases
When Microsoft® Jet manages a repository database, a special restriction applies to the use of multiple threads. Only the Jet-managed thread that created an open repository instance to a repository database can use the instance. In other words, if your repository database is managed by Jet, construct your application as if the repository were using the apartment thread model.
For more information about using Jet repository databases, see Reading Repository Data Outside of a Transaction.