Maintenance Plan Failed SQL2005

I am trying to create a simple Maintenance Plan using the Wizard to
backup my databases. When I click finish everything works fine apart
from the last step, "Saving Maintenance Plan". The report I get is
this
Maintenance Plan Wizard Progress
- Creating maintenance plan "MaintenancePlan" (Success)
- Adding tasks to the maintenance plan (Success)
- Adding scheduling options (Success)
- Adding reporting options (Success)
- Saving maintenance plan "MaintenancePlan" (Error)
Messages
Saving maintenance plan failed.
ADDITIONAL INFORMATION:
Class not registered

Class not registered
I have a standard installation of SQL2005 Enterprise and have made sure
SSIS is installed and running. Any ideas on what Class is not
registered and how to fix this would be greatly appreciated.
Although I haven't fixed the problem or found out which class it is
looking for I have found that this is only happening on 1 workstation.