Yes, I dug up this thread because certitude's down again. Oh, shoot! Now I've boosted this thread for another round this year. Well, I notice that at least people don't seem to pile on certitude even when it flakes out every other year, so I guess that's an implicit testimonial for it.
Seriously, I just put out my first puzzle cache and used certitude because that's what I saw the cool puzzle creators doing. Now a couple days later certitude goes belly up. Half of me is thinking it must be all my fault, the other half of me is wondering why I didn't listen to the wisdom of fizzymagic. I seem to make that mistake too often...
Certitude is down as noted in the profile:
http://www.geocaching.com/profile/?u=certitude
All geocheckers go down from time to time. I had the same problem when I used geocheck.org, geochecker.com, etc... Just need to be patient and live with it.