I'm using a 120 gig hard drive I purchased a couple of years ago on my 60 gig 360 (not a launch unit) and I couldn't get the campaign to start after installing the game (disk read error). I cleared the cache, deleted my old install and reinstalled the game and I got it to run.
Played all the way through level 7, and at the very end of the level the sound cut out during the cutscene and I got another DRE. Somehow the game still credited me with completing the level, so I missed the cutscene but I still advanced in the campaign.
I played all the way up to the last level. I'm pretty much at the end, but if I die enough times the game will just restart the level, instead of starting me back at the checkpoint.
I really expect a much better experience from Bungie/MS, especially since this is their biggest release of the year. Every time the game pauses to load my heart skips a beat, because I don't know if I'm going to get a DRE or if the level will just start from the beginning, therefore losing all of my progress. I haven't even attempted to play multiplayer yet because I want to avoid frustration.
A week later and still no word from MS or Bungie about a patch or a fix; it's getting a little embarrassing. It seems that everyone that calls MS gets a different "solution" - do they even know what's causing this? Seems like they are just throwing things at the wall and hoping that something sticks.