I can only assume there is something in the set-up of the source units that is affecting the so-called "handshake" with the monitor. The "dreaded" HDCP(High Definition Copy Protection) issue has to do with compatibility thru HDMI that is preventing you from getting the picture. Is your monitor set for 1080p or 1080i and is that in line with the PS3? As far as the cable box I am not sure what brand you have, but I, personally, haven't seen one YET that will pass 1080p OR 1080i pictures along with audio thru an HDMI connection. There is probably also an audio/video set-up within the receiver itself that will make the transition from source to monitor function correctly. That could also affect why you might not be getting a picture.
From my own experience with HDMI and all its issues, when you are using an AVR/pre-pro with recent technology, set-up from source to AVR to TV is vital because sometimes by just overlooking one thing, you will have the issue you are describing. NO PICTURE!
