My computer clock was gaining a few minutes per day, which made WSPR only work for a few hours, then the time blocks would be off. I couldn't find an easy way in windows to make my computer clock sync more than once a week.

I found this utility that will sync your computer clock to internet time as often as you want. I made mine sync every 15 minutes. This should be good...

http://www.thinkman.com/dimension4/