outlook project web access add in connection problem

[umutyes]

Dear All

i installed the outlook add in for project web access inorder to receive the updates for the tasks in the project.
The client can connect to the pwa with

http://server/pwa

thru ie 7.0 succesfully.

However when i try to use outlook and do update pwa or import new aasignments, it is saying `unable to contact Project server at

http://server/pwa`

When i check the event viewer, soap errors are showing as
-loading of the wsdl file failed
-xml parser failed
-one of the parameters supplied is invalid

ANY HELP IS APPRECIATED.

Thank you
UMUT