Default [Q] ART mode problem on NIGHTLY CyanogenMod 11 INTERNATIONAL

Does anyone had try the 'ART' mode under CM11 international ?
I had try it, on version cm-11-20140308-SNAPSHOT-M4-enrc2b it's really good
but yesterday I want try version cm-11-20140401-NIGHTLY-enrc2b and 20140407-NIGHTLY,
After flash it, my phone can't start any program! even default launcher(trebuchet) can't start ether

Does any one can help me?