I have seen quite a few searches for this warning in our stats, so I thought I would address the following message received when importing an application definition into the Business Data Catalog.
Could not create profile page for Entity MyEntity. The error is: Default action exists for application 'MyInstance', entity 'MyEntity'. Profile page creation skipped.
When you import your application definition, this kind of looks like an error but in fact is not. This is just the message MOSS gives when you add a default action to an entity. I describe how to do that in the linked blog post. Unfortunately, this appears as an error in the Event Log instead of a warning. This is unfortunate, because your MOSS administrator will likely ask you about it (my last one did). The long story short. Don't worry about this message. It is perfectly normal to receive it when you have specified a default action.