I would post your question over at AVS forum. Look in the plasma sub-forum.
*search for a thread on that particular LG plasma by using the model number. It's an older model, so there might not be much until you scroll back quite far in the archives.
I was able to hook up my Samsung SMART HUB Blu-Ray player Model BD-D5300 to my roomate's 2007 LG 50PC5D-UC Plasma television.
I set the Blu-Ray player to 720p and successfully connected to the Smart Hub and internet connection.
All still pictures show fine. Whenever you try to run a video (in this case it was through HULU Plus) I got audio but the video was just a blank turquoise screen.
I found something about possibly needing to update the firmware on the television, but have unsuccessfully located how to do that for this model.
Am I doomed with this combination of electronics to stream video?
Thanks in advance!