Baby Chee...
I realize this is an older post but I thought I would chime in anyway....
The biggest threat (at least in my experience) to a Stilton variety is the possibility of it becoming "liquid" from too much humidity.
I personally have never had this happen but I have read of it happening on a couple of different forums.
I have never had a Stilton style of cheese go bad and I will say that, in my opinion, they have a horrible smell while aging. Not a rotten smell, but certainly not pleasant or nice.
My wife and my kids will run shrieking from the room if I tell them I am about to open the Stilton cave. That's when I know I have a good one going.
Oh, just to whet everyone's appetite on this Thanksgiving day.....
One other problem that I've read (more than once) concerning a Stilton style is that it is susceptible to maggot infestation. Doesn't that sound nice?
Okay, I've typed too much.
Dave