too old?

I’m using Audacity 1.3.13 beta-unicode on a Mac OS 10.6.8. (I will get a new computer with Yosemite in August) I can’t fade out music. Everything is greyed out under Effects. Is there any hope to add this effect on this computer and with this program. Will the later versions of Audacity work on this old mac?

The effects turn gray when you’re in Pause instead of Stop.