incorrect chip time

I finished the Philly Marathon yesterday and my chip time on the results yesterday was 3:59. Today it is 4:01. Why the change? My watch said 3:59 too. Anyone else's chip time change overnight?

My chip time remained stable overnight, but it was about two minutes greater than what my own watch said. I attributed the difference to my fumbling around with my watch along the way, trying to look at splits and possibly stopping my timer for a short time by accident. But now I wonder.

I also heard rumors that the mile markers were off early in the race -- talked to someone who said he saw a thread on a forum somewhere. My friend's and my observations during the race are consistent with that hypothesis. He saw mile markers, looked at his watch and said, dude, either we are going way too fast or the marker is substantially off. Getting false feedback about your pace is unhelpful. But I digress from the topic of your thread -- sorry :-)

My gps was also off from the mile markers.  I ended with 26.42 which over 26 miles I just thought I must have run the apex differently than what I should have.  However, I was off by .1 mile very early in the course and kept hoping a mile was off and it would all even out.  It did not.  Combine that with the fact that 1:29 was added to my chip time overnight has me very upset.

Looking at my splits (and others have confirmed this) mile 4 was long. But 5 was short. Overall I think the course was fine. Using something like a Garmin Forerunner to measure a race course doesn't work as the GPS is not accurate enough. Nor can you run the tangents the way the course is measured when you are running in a crowd. Finally, every course has a fraction of a percent added on to ensure that the course isn't short.