Okay guys, don't know if anyone's had this happen, but this what just happened to me 15 mins ago:
I recently brought my 1yr-old JP PS3 to my bro's place (lending it to him so he can play MGS4). So I bring it over, set it up, setup wifi network, and then it's go time: Inserted the MGS4 disc...

...and nothing happens. Disc does not appear anywhere in XMB.

I eject and re-insert multiple times, and nothing. The PS3 loading icon appears in the top-right for a while, then nothing. I can definitely feel the BD drive spinning the disc for a while though.

I even tried the bonus disc, and nothing, not detected. HOWEVER (this is where it gets a little interesting), I tested a pirated DVD...

...and that works. WTF?

The JP machine is currently only at FW2.30, and it was asking me to update to 2.36 but I ignored it cause I tried to update but it took forever and kept disconnecting from the main server. So I figured I'd wait for tomorrow's 2.40...

So can anyone tell me what the deal is?! Everything else works fine; plays demos and videos of the HDD, plays DVDs, but not BDs?!?

I'm hoping tomorrow's FW update will fix things, but if not...do I have to replace the lens? Tomorrow I'll be going back with a couple more BD games, movies, PS2 original games and movies and see what it can/cannot play.