There have been issues with the autofocus on the Motorola Droid phone, which suddenly resolved themselves this morning and led to speculation of a stealth update. There is a fascinating comment in the Engadget forums by Dan Morrill (and noted in a tweet from Matt Cutts):
There's a rounding-error bug in the camera driver's autofocus routine (which uses a timestamp) that causes autofocus to behave poorly on a 24.5-day cycle. That is, it'll work for 24.5 days, then have poor performance for 24.5 days, then work again.
I suspect it is exactly 24 days, 20 hours, 31 minutes, 23 seconds, and 647 milliseconds, the amount of time for a millisecond quantity to overflow a signed 32 bit integer. This is a relatively common programming error, and one which can slip through a compressed QA schedule. In the case of the Droid, the camera was working fine while the QA team tested it and then stopped working slightly after the product shipped.
