Hey, after having no luck finding the answer to this on the Internet either for months I decided to give Philips a call. Here's the answer:
1) Unplug your TV from the wall and wait about 15 seconds.
2) While TV is off, hold down the Power button on the TV and plug the TV back in while holding the Power button down. TV should come on momentarily then shut off again. Release Power button.
3) Turn on TV again, press the CC button on the remote to cycle to "CC Off".
4) Turn off the TV and wait 15 to 30 seconds.
5) Turn on the TV and captions are gone for good!
Applying AC power to the TV while holding down the Power button resets the TV to factory settings. How the factory settings change the CC I have no idea but this trick worked for me. Hope it helped!