Microsoft unveiled Photosynth only yesterday (Wed, Aug. 20, 08) but seems to have seriously under estimated how many people would try the service in it’s first hours. Indeed, I found that two of my Synth’s had just stopped. I have to recreate them now. No biggie, I was just playing around, but it demonstrates that people are really excited about this technology. The service was actually unavailable for a few hours today. Microsoft, in an effort to control the service, throttled the uploads back for a few hours. They then attempted to tweak the database but actually introduced problems. The problems caused a number of errors for a few people. They rolled back the database changes and brought the service back online. They are still experiencing some problems, but most seem to be resolved.
Go here to read a short explanation for some of the problems.