Disk Quota isn’t working

I turned on disk quotas on my server. I read the manual to double check if I was doing it right, because it isn't working, and I am. Simple check the the check box for the drive in workgroup manager, then just give each user a quota. But I can fill each user's home folder right past their quota like its not even there. Has anyone else had this problem? And if so, what was the solution?