Post your question in the Mailbeez support thread, that way you'll get the attention of the mod developer.
I too, am having this issue. I've looked at my config.php, and it IS correct. The problem originally only occurred when accessing from certain PC's, but since all of my PC's are now running newer IE's, I get that message every time.
I've looked thru the 80+ pages of the mailbeez forum on the zen cart site, but haven't found an answer to this particular problem. I am hoping you did, and can pass the info on.