At least on a Mac Audacity seems to have issues when it comes to using third party plugins (i.e. AU or VSTs). To pinpoint which type of plugin is responsible for poor Audacity to crash, you can do the following.
I. Locate Audacity Config File
On a Crapple Mac the audacity.cfg file should be located here: /Users/<your-username>/Library/Application Support/audacity
The platform independent and Open Source driven audio editing software Audacity has been released in version 2.0. Audacity is available for Windows, Mac OS X and Linux. Many people say, Audacity is simply one of the best software audio editors with a huge amount of well designed built-in functions (fading, normalizing, vocal remover etc.).
Although the GUI should imho still be enhanced in comparison to its commercial competitors (Steinberg Wavelab, Sony Soundforge, Adobe Audition etc.), Audacity is a must-have, as it is free and from a technical point of view it is impressively powerful.