Try running it and when it freezes do a battery pull then run again and it usually works.
I have tried 7 times to use the z4root and no luck. Unknown sources is checked, USB debugging is checked. The apk is copied directly to the sd card. I get the z4mod screen and have tried to do permanent root. It just sits there and runs with "Running exploit in order to obtain root access..." at the bottom of the screen. I have let it run for 10 minutes. Stopped the application and tried over and over, letting it run different amounts of time....still no root access.
sigh......
I have a DROID2 GLOBAL, Android version 2.2
Any thoughts?