The issue is a ClearCase setup problem. Basically your ClearCase client installation is not telling the system that it is supposed to be the SCCAPI installed provider for that machine.
This article looks related:
OPM is looking to see if you have anything installed using the SCCAPI. It does this by looking for the registry key mentioned in the article I linked to.
If there is no registry setting then OPM says "This person does not have anything to do SCCAPI so I will not show those menu items". If it is there it will try to use that provider via the SCCAPI.
I've never seen an installation of ClearCase where it actually set up these registry values properly so I think you will have to edit the registry yourself - giving it the values as per the article I linked to rather than trying to reinstall.
So no you should not need to make any changes to OPM.
I do not think that reinstalling ClearCase will help because I do not think it tries to set these registry keys on installation (but I could be wrong).
What you will need to do is to make sure the registry is updated as per that other article. I realise it is for another product (not OPM) but it is setting it up ClearCase so it is reporting itself to be available in the same way.