Project server professional login problem

[Ash]

Hi All,

We have EPM, PS 2K3 and it's running on 2 load balanced front end
servers.
The prob is, when we try to connect thro' PWA, we are able to access
the same seamlessly from both the instances.
While accessing thro' Project Professional, one of the instance
connects without any problem but the other one throws the error
"Unexpected server response..............project server has returned
the unexpected server response....Click on view button to see the
server response. "

After clicking on view button, it gives: "The server at 'http://
Servername/projectserver/' returned the following error to Project.
"INCORRECT FUNCTION"


Please advise, thanks a lot in advance!


Regards,
Ash