Best way of modelling events?

[wsargent]

I'm dealing with a number of systems that use an IoC container, and fire events off to listeners that are defined at runtime.

This makes defining class diagrams a little sticky -- I know that there's an association between two classes, but there is no class level association there.  Should I imply a dependency, use the IoC container as the association class or just link them directly?

Also, I'm not sure how best to model events.  Is it better to model the event explicitly (with a signal event) or just assume it exists in the activity diagram?  

Also, the IoC container tends to package up class instances as 'beans' or 'components'.  Should I be using a component diagram to detail these configured instances, or is this something that can be handled in the class diagram with stereotypes?