Question on receiver lights

[DutchBoy]

Okay -- hope I'm not displaying too much ignorance here, but I had a question about the lights on my receiver's display (Sony DG720).

I was bitstreaming Return of the Jedi for my kids to watch tonight, and it's in DD 5.1 EX format.

When the signal hit my receiver, i saw the audio type being received flash by, and it said: "Dolby Digital EX 3/2.1" -- leads me to believe it is indeed processing the EX signal (or, at least, it knew what it was receiving).

My question is I'm wondering why the little "EX" light next to the dolby signal on my receiver isn't blinking on as well. The only reason I'm asking at all is to make sure my receiver is set up right and doing what it's supposed to do. Maybe it's something with the PS3, or it being a 5.1 signal, or something...

Anyone have any thoughts? Not a huge deal, just something I wondered about. Anyone else with a receiver EX capable and a copy of a DD 5.1 EX movie want to pop it in for me?

My thinking was it's not lighting up because it's a 5.1 and not a 6.1 or 7.1 track, but I really have no idea...