If you are running Project Server 2003 for EPM, and start to connect using the Project Professional, you may face errors filling up the Application log in the eventviewer. The error description is really unuseful, below is the error details:

Source: PjTraceSvc

Event ID: 2

Description: Lot of non useful information and something like:
C:OfficedevprojectWebClientsourceserverpjdbcommMain.cpp

However, you may find it deferent in file name, but still the same at the end.

If you look over the Internet, or in Microsoft KB you’ll find very few resources handling this, and even these resources do not address the same issue you have.

SO, what the hell is going on? Well, apparently the project server development team never bothers resolving this issue as Project 2007 is in the market. But if you are still running the 2003 version and this error really annoying, then here is the really bad news, you can (and in fact you should) ignore it as it has no effect at the operation of the server. All what this message USUALLY is tilling that someone (may be a PM) is trying to access/modify/update/delete an object which he/she doesn’t have an authority to do.
Yep, that is the story, I’m sorry but hopefully you didn’t spend more than three months moving from one expert to another to solve this issue as I did.