Just to add to the hunt for the cause:
After working with Shane Scott for quite awhile, we couldn't find the issue. So I reverted back to a backup from 5 days ago. All was working well there. From this point, I went and changed the production state on 4 different devices, individually. After the fourth device, my web interface stopped responding. This lasted about 10 minutes before I decided to issue a 'zenoss restart'. This fixed the web interface and made it respond again, but now my events are back to having the same issues. Looking to see if I can find anything different at this point.