Jaggies?! What am I doing wrong?

[Bluray_ne1]

I was watching the John Mayall & The Bluesbreakers BD last night and had paused it to hit the john. As I sat down, I noticed some blurring along the edges of otherwise sharp lines. When I got up for a closer inspection, I found there were jaggies all over the place.

It shocked me for a moment, considering the BD received a 4.5 rating for the picture quality. I checked the BD info and it is 1080p. The signal on the tv was 1080p also.

I must admit my ignorance on the subject, so I ask, what was causing the jaggies? Is it the settings on the PS3 or tv? Is the A/V receiver the culprit (It's my understanding that when using HDMI the signal passes thru and is not processed by the receiver). Or do they exist in the BD and the reviewer just missed it (I doubt it, those guys are sharp). All I know is, if it's my gear, I want to correct it somehow. I don't have the BD anymore (NetFlix rental already returned), but some of you who own it might be able to tell me if it's the BD. If it's the equipment, what would cause jaggies on a 1080p source and signal?

Edit: I stand corrected. The video resolution is 1080i on the BD, not 1080p. That may or may not answer the question.