worksheet change event with .NET interop
 

I'm currently writing a .NET application that is monitoring excel for cell
change events, then building a packet that is pushed into a queue waiting to
be sent to a server via a socket connection.
This is working wonderfully except that when I create the packet for the
queue, my app stops receiving worksheet change events. The app is still
functioning fine and Excel is also responding normally. The event simply
stops showing up in my app. No exceptions are being thrown. Other events are
working normally, workbook close events, open events etc.
I know it has something to do with the creation of my object, as I can push
simpler objects into the queue just fine.
Has anyone heard of anything like this with Excel? Perhaps give me an idea
of what to look for that would cause events to stop coming from Excel?