Wirelessly posted (iPhone: Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420.1 (KHTML, like Gecko) Version/3.0 Mobile/3B48b Safari/419.3)
please don't cross post in multiple forums. In answer to your question, i've had no problems with 10.5.1 (or 10.5.0). 10.5.1 has some important fixes in and you should probably update. However,10.5.2 is probably just around the corner so you could wait. Any update will result in some people having problems and people will always be more likely to post here if they've had a problem than if they don't so it does tend to present a worse picture than reality.