This is from RIM's site. As given above , RIM now looks for the PIN number in its data base via the internet connection and by default it requires the Data Plan.
BlackBerry Desktop Manager prompts that an Internet connection is required to configure synchronization
Overview
To synchronize organizer data for the first time between the computer and the BlackBerry smartphone, the BlackBerry Desktop Manager requires a connection to the Internet.
The following error message appears when organizer data is configured for synchronization:
This computer must be connected to the Internet in order to initially configure synchronization settings. Please ensure that you are able to connect to the Internet and try again.
BlackBerry® Desktop Manager 4.5 to 6.0
Cause
An Internet connection is not available, or the request is being blocked by a firewall, a proxy server, or a security application such as Norton AntiVirus™ or McAfee® antivirus software.
Resolution
Complete the following troubleshooting steps to determine the cause of the issue:
Verify that the Internet connection is functioning.
Confirm that the BlackBerry® Desktop Software is not blocked by a firewall or antivirus software. For more information on how to verify and configure access on a firewall or antivirus software, contact the software manufacturer. Examples of antivirus and firewall software are:
Norton AntiVirus™
McAfee®
ZoneAlarm®
Kaspersky® Internet Protection Suite
For additional information on the Windows Firewall, visit the Microsoft Support web site and search for "Understanding Windows Firewall settings".
If the computer is on a home or corporate network, confirm that the BlackBerry Desktop Software has access to port 80 and port 443. If it does not, allow access to port 80 and 443 in the firewall and proxy server settings.
If the computer is on a corporate network and a proxy server is involved, confirm that the proxy settings are enabled and correct in Windows® Internet Explorer® (Internet Options > Connections tab > Local Area Network (LAN) Settings). BlackBerry Desktop Manager 4.7 is now proxy aware using Windows Internet Explorer settings.
Install a packet capture tool (such as Wireshark®) and record the network traffic between the computer and
Smartphones, Cell Phones & Smart Phones at BlackBerry.com to confirm the port access and connection protocol required for the BlackBerry Desktop Manager.
Additional Information
When activating certain features in the BlackBerry Desktop Manager, the personal identification number (PIN) associated with the BlackBerry smartphone is registered with Research In Motion.