Inputting the network settings for any device can be a pain. Here you can download a wizard to automatically put in the correct settings for your p3600:  http://www.europe.htc.com/support/software/htcp3600.html    

Have you bought a P3600 before May 2007 ? You may or may not know that contained within its shiny sleek interior a GPS (Global Positioning System) satelite navigation chip lies dormant. Those nice people at HTC are giving a free firmware upgrade to switch on this hardware. See here ...