Seems if you zoom out to much, the zoom to fit does not work, it won't allow me to click the button. To make it work, I have to zoom in , then I can click the button, and it will auto fit.
I've got Sept 9th's 0.9.6 on WinXP pro VMWare 32bit under Ubuntu 64bit, with jre-6u34-windows-i586.exe w/ Open Logic Sniffer 1.01 Firmware 3.07, protocol 2.
I just noticed that the zoom - button goes grey, yet the mouse allows me me zoom out. So this is likely a problem with the mouse zoom limit. At the min scale, when the zoom + bottom goes grey, the mouse can not zoom in any more. So the min limit seems OK, just not the max limit.