Best places to start to track down what's causing the problem (usually a 3rd party shell extension or video codec):
[ul][li]Crash, exit or high CPU usage when viewing certain directories[/li]
[li]Crash, exit or high CPU usage when right-clicking certain files[/li]
[li]Crash dumps for bug reports (you can email them to leo@gpsoft.com.au)[/li][/ul]