Hard Drive Fragmentation

I'm almost certain there wouldn't be an issue... but having used pro-tools on my powerbook in the past...

Are there any issues with hard drive fragmentation when using Avid Express on OS X?

its possible , and i have heard of some people having fragmentation issues with protools. But i havent heard of any problems with the avid programs.

When you say it's possible... are you referring to normal disk fragmentation as incurred by normal usage... or could it crash my entire system?

I used FCP for several years on other's computers and have never heard of this being an issue with FCP.