imac crashing help please!

[Kajen]

My imac keeps crashing when I am trying to import sound fx from an external drive,into protools LE. It happens when I am just browsing sounds, I'll click on a new sound to preview and then the wheel of death will appear.and the computer wont do anything. this does not happen when I am acctually bringing the sounds into protools,only while I am previewing them, either from workspace or from the "import audio to regions list". any protools users with any suggestions?? or any suggestions at all would be great! thanks