webservices method to create a pdf file works fine in developer machine but not in the webserver

The webservices I have developed is to create and write a pdf file in a specified directory using the document printer SDK com object. This works fine in development system, but when deployed into the webserver the file is not created. All the other methods of the webservice work fine expect this method which is to create and write the pdf file into the specified directory. When i copied that pdf file from developer machine to the webserver folder the webservice method works fine. Is that i am missing any ASP.NET security issues in the webserver that blocks to create a file ?. My webserver is windows2003