Lookie what I found guys!!
From: TreoProTricks.com
Disable the Wireless today plugin
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.
I have confirmed this works, however you will need to soft reset once completed.
ENJOY!! =D>