Outlook Express problems

I have a user who shares his computer with one other user they each have their own profiles. When user 1 tries to open up outlook express to check his email, he gets this error…..
MSIMN caused an exception c0000006H in module DIRECTDB.DLL at 015f:5f585460 ………

there are more numbers didnt think they would be needed.
When user #2 opens her outlook express to read her email it works fine?

Any ideas folks? If I get a speedy response and can fix this today i may award more points Thank you in advance