After upgrading ADP1 with 1.6 , the root access has gone.
It can be recovered with adb tool:
do adb to the phone
$adb shell
$mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
$cd /system/bin
$cat sh > su
$chmod 4755 su
Ref: http://phandroid.com/2009/04/29/adp-15-initial-thoughts/