MacBook Pro Freezes when I close the lid without shutting down

Lately my Macbook pro freezes when I close the lid without doing a proper close down. After closing the lid and then reopening it some time later, the signon screen appears but the cursor does not appear and you cannot click on the password box to enter your password. Only option is to use the turn off button and kill the laptop. If you then press the power button again it fires up as usual, asking for your password.

Anyone know this is happening and more importantly how to fix it.

Thanks

Peter