last week i downloaded the driver and plugged in my ps3 controller into my computer. i configured it, installed it and it worked fine! it regesterd and everything!
however, today i turned on my computer, started up the driver, plugged in the controller and it didn't work. i went to control panel and under the ps3 controller it was regestering any of the buttons i pressed. the red lights stopped blinking after some time too, which was different, because when it did work, the lights were on for quite some time.
I know I have had some problems with USB controllers when I would just unplug the controller with out using the icon in the systray that says remove hardware safely that pops up in windows xp. Try uninstalling everything dealing with the controller and rebooting and installing all the software for the controller. When you remove the controller use what I spoke about earlier.