I had a Philips 42" LCD with ambilight a year and a half ago and I had nothing but problems with it. I did have to do a firmware upgrade myself which fixed the menu problems I was having. Just go to Philips.com and see if your specific model has a firmware upgrade available. If there is, download the file and save it to a usb flash drive. Turn your HDTV off and insert the flash drive and then turn the HDTV on. A menu will pop up and automatically start the upgrade or just manually start it yourself, I can't remember.
Philips actually treated me very well and service person was knowledgeable. They sent me a usb flash drive with the update on it for free. But, I would never purchase a Philips, or for that matter, buy anything from Best Buy ever again.
Here was the thread I posted on Audioholics about my whole ordeal with my Philips:
http://forums.audioholics.com/forums/showthread.php?t=27606
Many people have stated that Philips HDTV's have the most problems out of any other company. I was able to switch my Philips for a Samsung finally.