General Support: Log in issues

Hi there

I've installed plogger and can access the admin area etc. The problem I have is I use zen cart, but since installing plogger I cannot login into my zen cart admin it uses the same sql database and the username and passwords are the same I think. Here is the error

0 DB_ERROR_NOT_CONNECTED
in:
[select * from project_version WHERE project_version_key = 'Zen-Cart Database' ]
If you were entering information, press the BACK button in your browser and re-check the information you had entered to be sure you left no blank fields.

If anyone can help that would be fantastic as I'm really stuck.

Thank you

Silvermclaren