actually i found the answer after deeper research, and it works
If you have a * rooted * phone (phone must be rooted) and you can only
view your phone with androidscreencast, then following these
instructions to control it:
1. Download and install the BusyBox app from the Android Market on
your phone.
2. Open the BusyBox app and use the program to install the latest
version of BusyBox to your phone. Having the latest version of BusyBox
installed on your phone is important to ensure the following adb
commands work and to maximize your root capabilities.
2. Run the following adb commands and watch your phone display to
grant permission for the code to run from the superuser app:
**** CODE FROM USER JOSH GROCE - THANK YOU JOSH ***
adb shell
su
chmod 777 /data/dalvik-cache
cd /data/dalvik-cache
exit
exit
3. Reload androidscreencast and start controlling your phone!