Can't login to Mac after it's been sitting a while or goes to sleep.

I am running OS X 10.9.5 but have had this issue for a few updates now.

If I lock my Mac for the evening, when I go to use it in the morning most of the time it will not accept my password.

I can login as another user but not as the one I was logged in as before when I locked it. I have to force a reboot and when it comes back up it will allow me to login. We are using Active Directory for our accounts and nobody else has complained about having such an issue.

This is annoying if I left something up on my desktop and forgot to save it and just wanted to lock my computer for security.

Basically I have to save everything and close everything before locking the computer and leaving.

Also I'm running VMware 5.0.5 and can VNC from another computer into the virtual machine but can't login to the host system.