URL reporting export to pdf problem

We are using SAP Business Objects 4.1 and attempting to use URL reporting to export crystal reports to PDF. We have been doing this in BO 3.x releases and just upgraded to 4.1. Now when we programmatically try to export to PDF we get an HTML formatted message with a NULL crExceptionText. I think I have narrowed the problem down to the http request we are issuing has a null User Agent string. I changed the way I issue the request using PL/SQL to set the user agent string to Mozilla and now we get the PDF returned. Has anyone experienced this issue or is this a known issue? Any help appreciated ....

Thanks,

Tom