Strange require password window after sleep problem

Hi

I've been having a annoying issue with the require password window that comes up after sleep. I used to just hit a key on the keyboard, the MBP would wake up and immediately I could enter my password. Now, the password window appears, I start typing but then the window disappears and then re-appears while I'm typing, forcing me to select the password I had started writing and re-type it.

Small issue, but incredibly annoying over the course of the day. Any ideas where to start troubleshooting?

Thanks!

 

Nobody?