On pets http://area51.stackexchange.com/proposals/44686/pets the committment was listed at 58% in big numbers and 59% in the details. It had been this way for a couple days, I have attached a screen shot. Of course as soon as I started typing this Question it self corrected.
Is this system error, or something to do with my cach?
This is simply an artifact of caching, and is usually the culprit wherever you see two numbers that supposedly represent the same thing differ slightly. You'll notice this on Pets SE when it moves into the private beta, until a few hundred questions get into the system.
It's a small performance trade-off to eliminate quite a few queries on each proposal load, otherwise it would have to be calculated on the fly (from all factors that influence the percentage) and that would be considerably slower.
