I just bought Apple TV for my Plasmavision p42vha40 and cannot play Netflix due to HDCP non support. Is there a problem with this Monitor? A firmware upgrade?

This TV has an HDMI input, so what do you mean by
"will not accept any external HDMI-HDCP source"? How to... http://service.us.panasonic.com/OPERMANPDF/TCP55VT30.PDF

Some TV's & cables are not HDCP compliant . Sometimes you can replace the cable to fix the problem & other times you have to replace the tv because its not HDCP compliant . First check to see if your tv is HDCP compliant .

as far as i can tell this monitor is not HDCP compliant ( High Def Copy Protection ) and therefore will not be suitable as a TV monitor. Computers can use non HDCP compliant monitors but TV Tuners, Satellite Receivers, DVD players etc with HDMI are HDCP compliant and must have a HDCP display... HDMI has two formats basically HDCP and non HDCP

The model number with year set made is on the rear of the set unless removed (bad sign if removed)

Google each model number with "specifications" to see if both Have HDMI inputs, you should be able to see them in any case and the menu which shows input will if two label them HDMI 1 and 2.

http://manuals.info.apple.com/en/AppleTV_SetupGuide.pdf

You have not set up your router correctly.

Ok, I need more verifications:
1) Your TV is Fujitsu Siemens PlasmaVision P42VHA40 Monitor which does not have tuner? If not, please provide the make and model of the TV.

2) What kind of cables you are using to hook between the cable box and the TV? HDMI? Component video (Red, Blue, and Green cables withe RCA plugs)? Composite video cable with Yellow RCA plugs?

3) Are you trying to get the sound to come out off the TV speakers or through the stereo system?

What is a HDCP error? Here is a real life situation that happened that could happen to you. You just bought a Blu-ray Disc Player and connected it to your older HDTV with a HDMI cable. When you tried playing a Blu-ray disc a HDCP error was shown on the screen. The movie wouldn't play.
This is a known issue with HDCP, and it's one of the biggest hassles consumers will have to deal with when utilizing a HDMI cable on their HDTV. You will get a HDCP error if you try watching HDCP encoded content when using a HDMI cable.
The problem is that if HDCP exists anywhere in the video stream then all devices and cables accessing this content must be HDCP compliant. If one device or cable isn't HDCP compliant then you get a HDCP error.
The only solution is to either replace the HDMI cable with a non-digital cable or replace the HDCP-less device. This could mean buying a new HDTV. In fact, I worked with a reader last year troubleshooting a HDCP error on his TV. What happened is that he bought a Blu-ray Disc Player and connected everything properly only to get a HDCP error. After a few emails back and forth we discovered that his HDTV wasn't HDCP compatible, which is why he got the HDCP error.
The reader ended up buying a newer HDTV with HDCP, and his Blu-ray Disc Player worked perfectly with HDMI cables.

well this is easier than you think, get yourself a set of RCA's (the red and white and yellow cables that DVD players come with) look behind your decoder and place them colour to colour, then behind your Amp you will read (TV IN) do the same, then with just one yellow RCA plug it into (monitor) that one will then go to the (AV input) behind your TV.. And presto!!! now set your amp input on the remote to TV and your off!! good luck

The HDMI cable was causing "Display connected non-HDCP compliant" error message to appear.
When I reconnected my DVD to TV using regular cable with 3 color connectors(i don't know what is the proper name for that cable) that error message no longer appears on my screen and I was able to watch my movie normally.