This is why we advised not upgrading to Pro Tools 9 straight away. (But now you can!)
When Avid's Pro Tools 9 was released, we published an article that recommended not upgrading yet.
Why? Because every time you change your computer setup in any way, you take the risk that it won't work properly. This includes installing upgrades, updates and even other software completely unrelated to audio. Everything carries a risk in greater or lesser proportion. If you have a business to run, you will think very carefully before making any changes.
Of course, you do have to upgrade eventually or you'll fall behind in the game. Upgrading brings benefits, so you will trade these against the risks.
But some commenters thought that we were being unreasonably negative about the new release of Pro Tools. Well we have nothing against a 'fly by the seat of your pants' attitude if that's what you want to do. But we don't do it here and we don't recommend it.
But now, Avid has released Pro Tools 9.0.2, together with a list of problems corrected in the new update. Here is their own list of problems you would have suffered had you upgraded to Pro Tools 9 straight away...
Phew, it's quite a list! Granted, no-one's workflow is so complex they would have suffered from all of these problems. Even so, it seems that it would be a bit of a slalom not to hit any of them.
It's worth saying that we praise Avid in their work to improve DAW recording for us all, and we admire their openness in publishing this information.
However, we advise Audio Masterclass readers to continue to put their music first and their upgrades/updates, of any DAW or other software, second. Let someone else find out all the bugs!