This started happening to me as well after the 10.5.5 update. My less than a year old MacPro (2 x 2.66 GHz, 9 GB RAM) consistently comes to a crawl every thirty seconds to 1 minute. Sometimes it sets there for a few seconds. Occasionally a minute or two will pass before things catch up. I'm also experiencing the occasional graphic artifact (pieces of windows popping up in the wrong places, strange distortions at weird angles across the screen). I've rebuilt permissions, ran disk utility, watched the Activity Monitor for anything strange, and I see nothing out of the ordinary. However, I can boot into Safe Mode and the symptoms go away. So obviously this is the work of something running in the background which doesn't load during Safe Mode. My question is, how do I track down the culprit? I've started by disabling all my start up items and turning off any non-essential Preference Panes. But that has had no effect. I don't know how to remove, uninstall or otherwise disable all those other background processes to troubleshoot which one is screwing things up. Any ideas?
