I knew the Adobe Reader update process was bad, but I didn't know how bad until I accidentally installed 7.0.0 somehow on my laptop. It proceeded to download little updates to get me up to the current 7.0.8, and then apply them one by one. It took five reboots to upgrade Reader entirely.
That's five more reboots than necessary, and four more than reasonable. Reader insinuates itself into your system at boot time and inside MSIE, so they have a hard time upgrading it. But applying multiple patches and reboots is really dumb. Dear Adobe: people put old versions of your installer on their CDs. You should support them well.
Some help for you. PDF Download does its best to prevent PDF from ever loading inside Firefox and corrupting it. Adobe Reader SpeedUp fixes a lot of problems in Reader and lets you disable autoupdates. And Foxit reader just hit 2.0. I don't like the rendering in this Adobe alternative, but it is an option.