Strange event receiver behaviour

I've written and deployed a feature. This feature has 3 event receivers.

Each event receiver is tied to its own list using <Receivers ListUrl="Lists/Registrations"> in its respective Elements.xml file.

When I go through and test the receivers they all work as expected except they will often given the returned message (properties.ErrorMessage) of one of the other event receivers!

Could this be a caching issue?

Also, when I attempt to delete a shared document I get the message that only site admins can delete the document (which is how one of the event receivers works on a different list)... none of the 3 event receivers have anything to do with the shared documents library!

The 3 event receivers are tied to the follwing 3 custom lists

<Receivers ListUrl="Lists/Registrations">

<Receivers ListUrl="Lists/PastRegistrations">

<Receivers ListUrl="Lists/Courses">

They are all bound to the ItemDeleting event.

Any ideas?