I searched and could not find the patch, but I found this solution:
Solution ID : 548
Incoming call does not audibly ring, vibrate or appear on screen, it goes directly to voicemail.
Normally, when an incoming call arrives on your Windows Mobile® Treo™ smartphone, a number of things should happen to let you know the call is waiting to be answered:
- An Incoming Call alert appears on-screen, including the phone number of the person calling.
- If the ringer switch is on, your smartphone will play a ringtone. Depending on your settings, it may also vibrate.
- If the ringer switch is off, your smartphone may vibrate, if you have set it to do so.
Why do the alerts not appear?
There are a few conditions that will prevent notification of incoming calls.
You are actively transferring data on a certain type of Internet connection:
Your mobile service provider may use different kinds of Internet connections, depending on your geographic location. Some of these connection types allow you to receive calls while actively transferring data; others do not.
For example, Windows Mobile offers two types of Internet connection: Broadband Access and National Access. You will not be able to select the type of connection, because it is provided automatically by the closest mobile radio tower. You can see which type of connection your phone is currently using by looking at the top of the Today screen.
Here is the catch: if a Broadband Access connection is active, you will be notified of incoming calls. When you receive the call, the data transmission is automatically interrupted. However, if a National Access connection is active, you will not be notified of incoming calls. They will go directly to voicemail.
Your smartphone's Password, Owner Information, and Ringer settings are obscuring the Incoming Call alert:
Your smartphone allows you to set a Password that prevents unauthorised access after a period of inactivity. You can also choose to display your smartphone's Owner Information whenever the phone screen is turned on (whether you turn it on manually, or it turns on automatically to display an alert). And finally, you can turn off the ringer by flipping the switch on the top of the smartphone to Ringer Off.
If all three of these settings are activated, the Incoming Call alert may not appear, and the phone may not ring or vibrate (even if you have it set to vibrate when the ringer is off). You will not be able to tell if someone is calling you, and eventually the call will go to voicemail without your knowledge.
What to do? Make sure these three features are not being used simultaneously. Disable one of the three features: either turn off the Owner Information setting, disable the Password, or turn the ringer switch to Ringer On.
If you must use these three features at the same time, expect to have some of your calls go to voicemail when your smartphone has been inactive long enough to trigger the Password function.
To turn off the Owner Information setting:
- Press Start
and select Settings.
- In the Personal tab, select Owner Information.
- Select the Options tab, and uncheck the box for "(When the device is turned on, display
Identification information."
To turn off the Lock setting:
- Press Start
and select Settings.
- In the Personal tab, select Lock. If prompted, enter your current password.
- Uncheck the box for "Prompt if device unused for."
To turn the ringer switch to Ringer On:
- On the top of your smartphone, flip the ringer switch to Ringer On (the solid icon of a speaker with sound waves emanating).
Remember, you only have to do one of the things above in order to prevent call notifications from being obscured.