Vista - Password not recognized after sleep or screen saver.

I'm having a problem accessing my laptop which is running Vista Home Premium. It keeps saying it does not recognize my password which I had used to access it only minutes beforehand. I know my caps lock button isn't on. When I reboot my computer I log in to my admin account with no problems. It happens when my laptop goes to sleep or my password protected screen saver goes on.

I have the same problem. I want to remove, change password and I cannot do either as vista says they are incorrect, but they are correct.
I cannot log in automatically because of that, because it says my password is inocrect, I enter it manualy and it's correct.
Basicly vista in some cases says that the correct password is incorect. Mostly in managng settings and so on.
Could anyone help?
I read some forums and don't want to do system reset, I worked hard to set up my system, adding functions and so on.