Installation of Arduino 0013 scrap 0012? (SOLVED)

Hi guys,
after it seams that i install Arduino 0013 i cannot compile (verify) anymore on arduino 0012???
i install arduino 0013 in a directory of its own and this is what happen as i try to compile BLINK.PDE which compile perfectly in 0013
i check the preference.txt file in lib and there is no build.target variable! and anything with the word build is exactly the same in rev 12 and 13!

Any idea.
Thanks in Advance, (i need that rev 0012)

java.io.IOException: Target platform: "null" not found.
Make sure that "build.target" in the 
preferences file points to a subdirectory of 
C:\Documents and Settings\Patgadget\My Documents\Arduino\arduino-0012\hardware\cores

      at processing.app.Target.<init>(Target.java:49)

      at processing.app.Editor$36.run(Editor.java:1390)

      at java.awt.event.InvocationEvent.dispatch(Unknown Source)

      at java.awt.EventQueue.dispatchEvent(Unknown Source)

      at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)

      at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)

      at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

      at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

      at java.awt.EventDispatchThread.run(Unknown Source)

i just reinstall REV 0012 from scrach and still have the same error!
:cry:

SOLVED !!!
As i install rev 0013 it was for testing on a Atmega328
as i went back to 0012, there were no board selected and that is why it gave me that error