Does masking prevent CLICK and MOUSE_OVER MouseEvents?

I had a dynamically created list of MCs that each had rollover states as well as click actions.  Everything was working fine...

...Since the list was longer than the bounding areas that I wanted it constrained to, I added a mask to the container MC that was holding the dynamically created list (using AS3 - not through right-clicking the Layers).  Now the list is still being generated, but the CLICK and MOUSE_OVER events are not working.

Does this make sense?  Is that how Flash operates?  Is there a way to prevent/fix this?

Thanks!