Microsoft 2003 error 1605 - Cannot run the add-in & incoming emails disappearing

When I start up Outlook 2003, I get the following error messages:
MOO cannot run the add-in
MOO cannot install the necessary files due to Windows Installer error 1605
Action is only validfor products that are currently installed.
I did reinstall MO 2003 with no luck in solving problem.

Additionally, all of a sudden my incoming emails go into my inbox then disappear one by one. They are not going into any of the folders I set up (with Rules).  Everything was working fine until a week again then these events started happening.

Thanks for you help,
Barbara