The password is valid, but is not remembered and for next sessions GiD is asking again for the password:
This problem is because the program doesn't has permission to write the password in the file \scripts\TemporalVariables
You must start GiD once with adminitrator privileges, and enter the password, then it will be saved in this file for next times.
To start GiD with adminitrator privileges:
- On Windows Vista/7
click the right mouse-button over the starting icon of GiD, and in the contextual menu select something like 'Start as administrator'
- On Linux
use the 'sudo' command (SuperUserDO),
(the administrator password will be asked)