This is really disappointing. This bugs the crap out of me and it hasn't worked in a few releases.
 
I have auto save set at 10 min or 100 changes. It saves whenever it feels like it, and usually at a work-stoppingly ridiculous frequency. I may audition a clip with a compressor on it for 75 seconds, and once I stop, the damn program starts autosaving.
 
Anybody else?

I dont trust auto save across ANY application I use, I turn it off and manually do it every key change that I have made.

try increasing the number of changes

Yeah brother. this also happens with me :D so i don't trust the auto save option now. :D

Never liked auto save. I save manually and use versioning (sp) to keep my last 20 versions. No more hassles. I don't use auto save in any of my computer work because it causes even powerful systems to hiccup at times.