I am using TCP/IP, not COM port. I can ping to the device, cant connect to the device.

I'm developing an application to talk to a rfid card reader using C#. The application works fine on Windows XP, but when it comes to Windows 7, i just cant seem to connect to the device. I can ping to the device, meaning there's connectivity with the reader. I have tried with both firewalls off (public and private) and have turned off my anti-virus software too, but couldnt. Any ideas? aHa