Originally Posted by masterbox
I am in the same situation, except for su and superuser.apk which are owned by root, and su also give me permission denied without launching superuser request.
You both have probably "untar'ed" it not
as root - and the "+s" flag has not been set up. Or on Linux box change right to those two files, or once again untar it from root account.
chmod 6755 /system/bin/su
chmod 755 /system/app/superuser.apk
ps. Since I haven't wrote it explicite, it should be from root account - I've corrected this in howto.