I tried Gears of War 2 & 3 and Fable 2, they all worked.

Perhaps bootlegs? 😉

Mass Effect ans Mirrors Edge worked find. Haven't installed other disc games so far.

Your Fable 2 works from the disk?  I don't know what the problem is with mine then.  I'm sure I have the standard edition. 

Everything works fine for me with the exception of Banjo and Kazooie Nuts and Bolts. In game videos I recorded are in slow motion when I view them and the frame rate is bad. Other than that though, everything's running fine.

Yeah, I have the UK version (standard edition, first print). The game runs okay, but has performance issues.

Just for the sake of wondering, your copies of the games are from the same region as your X1 was bought right? just if you happened to be living near any border regions north or south of the states, just a thought. Sorry I can't help you more but a call to xbox support is looking like your main choice here or else just sit back and wait til they iron over any issues with the BC, it is still the systems first week :) and you got Tomb Raider just after dropping to jump into! Lucky so and so!

I tried Mass Effect, it worked fine. Tomorrow i will buy Condemned: Criminal Origins retail disc.

Maybe you're not sticking it in deep enough

Haven't tried any discs yet as my BC have all been digital