Security right permission only remove in parent folder

hi,

I have a problem in Windows file system security permission in Windows Server 2008 R2 SP1.

I remove userA in parent folder security right permission, the child folder will not removed, and add userA right to every child folder instead, does anyone face this problem before, this isn't happen always but sometimes, e.g. 1/5 times.

Very strange problem I never seen before, how to troubleshoot?

Have a nice day

Thanks...KEN