The Wireless today plugin that links to the Comm Manager on your Palm Treo Pro is provided by HTC. On most HTC devices you can disable and/or rearrange it, however on the Treo Pro it is not in the list of today plugins.
Using a registry editor (or Total Commander) you can go to HKLM\Software\Microsoft\Today\Items\"Wireless". There you'll find a dword Enabled=1, set this to 0 to disable the Wireless plugin.