Why can't I access the /data directory with ADB on my Samsung Vibrant? I used Simply Honey before and everything was okay. However, when I flash to a Stock 2.2 ROM, I cannot access the /data directory from adb. I am sure the phone is totally rooted because I have the Superuser icon in my apps menu and I can open the /data directory in Root Explorer. Why can't I access /data from adb as well?
You need to escalate the shell, since /data requires root permissions to access.  After running adb shell, run su before running cd /data.  The prompt should change from $ to # if it works.