We've been getting a lot of alerts saying "Performance Module could not find a performance counter." It's been making me nuts. I finally did a search on the web and found an entry over on the Operations Manager Product Team blog. It's a known issues with SP1. I'm posting this, not because I'm complaining. I'm not. SP1 solved several issues that I had and I'm very happy to have installed it. Unfortunately, it introduced problems. Just not as many as it solved.