maybe a serious jdk bug on 64bit windows

I found a bug of jdk6 on windows 64bit. bad infruence on local variables not in multi-thread environment.
use -Xint flag or use x86 version jdk will not show this bug.
I think something wrong with JIT code in multi-core environment? I sumitted the bug to sun oracle but not yet be confirmed.
caution should be used when use 64bit jdk or just add -Xint at this time.