[ul][li]Try the steps in this FAQ: Crash, exit or high CPU when viewing a certain directory. Opus should not be crashing at all when you change folders so if it still is that indicates there is still a problem (usually caused by a shell extension and/or particular files in the folder which confuse some piece of code in Opus itself or in a plugin/extension). The FAQ explains how to track it down.
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[li]Also make sure your sound, motherboard and hdd-controller drivers (which may all be part of the same bundle, or may not, depending on hardware) are up-to-date.
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[li]If you were using a custom sound for the event (not the default navigation click.wav that comes with Windows), it might be worth checking if it still happens with the default sound, in case the crashing was due to the sound file triggering a crash in the decoder (which could involve audio codecs, too...)[/li][/ul]