ya know... I've tried that method and it messed up my ability to read from my internal DVD-RW. since I'm not a part of the dev group for snow leopard OR the 10.5.6 update I can only speculate as well and even then I hold my breath a lot because Apple surprises me around most corners with what they update and how.

One thing I do is to label all my extensions with a single color and then after an update I'll go through and check to see which ones were updated by booting to a different (stable) drive first before I go on to try and boot into the updated one.

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