Can't destroy blocks with diamond sword in creative mode !!!

i tried to destroy a block with diamond sword in creative, but it's like bedrock in Survival, i can't break it
please watch the video, it's a very serious bug!
what i expectet to happen, was that the block would break!
but it didn't
Later, i tried it with several tools, and i found out, that this bug concerns any sword of any material! I can't destroy anything that's placed in Minecraft!
In the video, i only tried it with a diamond sword!
hope you can fix it
if it helps, i'm on Mac osx 10.8.3