I did open my case, but I noticed there was no seal anywhere.
What I _DID_ notice is that there seems to be some sort of seal between the main circuit board (the one staring you in the face on top when you take the cover off) and the standoffs it is mounted on. My guess is that breaking that would void the warranty.
I couldn't resist the temptation myself http://www.avsforum.com/ubb/smile.gif! What was scary was to see how the RF output is wired up. It looks like they just packed off the shelf modules in there and just wired them up. I wonder how much that added to the cost of the unit.