run the auto-setup for the surround sound system. it should have came with a test microphone for this. once this setup is complete you shouldnt have any delays.
in order to use a ps3 with a lcd television it must be HDCP compliant. check this. next make sure you are on the correct hdmi input and the tv is set to channel 4. checking cable connections wouldnt hurt either.
note: if your surround system box acts like an A/V unit wouldnt the PS3 cable to that box instead of directly to the tv so that you get surround sound on the ps3? in which case usually you have to swap inputs on the a/v unit and not the tv.