I used to think these claims were a bit bogus. However, my macbook pro was locking up solid and completely unresponsive at seemingly random times requiring a hard-reset (running 10.5.x). The constant thread I noticed was that I was always using either NetNewsWire or Safari when it happened. I kept trying different things to fix the issue (erasing preferences, verifying permissions, etc...) but no luck at all. There was nothing in the crash logs and no kernel panic or anything like that for me to even trace the culprit. It would just completely hang without so much as a wimper.<p>The last thing I tried was that I installed click-to-flash. I haven't seen one of these crashes since. I thought for sure there was no possible way it could be flash since the mac usually does a pretty decent job of managing hung apps without bringing the whole system down, but for whatever reason it really looks like flash is causing this. I suspect it's some odd problem with my flash installation or configuration.