Lots of bloggers are jumping around with excitement today at the rise of the Feedburner counters. ProBlogger leapt from around 39,000 subscribers a few days back to 41,000 yesterday and 100,000 today.
Alas – it’s a bug and it seems that a lot of bloggers are seeing their stats are up. There is some discussion on the Feedburner forums here about it. Some are linking it to similar problems at Feedblitz.
All I can recommend is take a screenshot!