Firstly check if you have the latest version of the Jet 4 serice pack.
Locate msjet40.dll (usually in windows\system32), right-click, and choose
Properties. If the Version tab shows less than 4.0.8015, download the latest
from support.microsoft.com, under Service Packs. This article lists at least
one case where that message was addressed in the service pack:
http://support.microsoft.com/?id=259873
If that does not solve the problem, you could try rebuilding the mdb in case
it is corrupted. Details:
http://allenbrowne.com/ser-47.html
