Recently I created a web part for Project Server 2007 and I had to use PSI which is a set of web services which are coming withe the PS 2007 installation.
When a PSI web service is addded in Visual Studio to a project, the chosen web service url has the form of http://{machinename}/pwa/_vti_bin/psi/{webservicename}.asmx but in the app.config file and in the settings class of the project, for a reason unknown by me the url of the web service is set to http://{machinename}/_vti_bin/psi/{webservicename}.asmx, the /pwa part is left out from the url.
When accessing the web service, a WebException with the 'Object moved' message is thrown, which is not really meaningfull. The solution is to modify manually the generated url both in the app.config and in the settings file (Settings.Designer.cs).