Here's the scenario:

I gave my old phone (Razr v3i) to my son, and I put in a new SO sim.
The setup works wonderfully, except my son cannot call my Rogers cell number.
When he calls my Rogers cell number, he gets direct access to my voicemail.
He can access his own SO voicemail box without any trouble.

I'm not sure why he's able to access my voicemail directly.
Here's what I know:
1. The Razr used to have my Rogers sim and services.
2. the Razr is a non-Rogers purchased phone.
3. the sim is a new SO simcard.
4. when I registered the SO sim, I entered the Razr IMEI.
5. on his phone, I erased all phonebook contacts, and entered in new, my cellphone number.
6. on his phone, I erased all shortcut keys – "#1" used to access my Rogers voicemail.
7. on his phone, I entered the SO voicemail retrieval number under #1.
8. on his phone, I double-checked the #1 shortkey goes directly to the SO voicemail (which has a different security passcode as mine).
9. To access my Rogers voicemail, I need to call a voicemail retrieval number that isn't the same as my cell number.

Any thoughts or comments? The reason we setup my son with a SO, is so he can reach me when he needs to. Right now, that's not working. Help anyone?

***
Forgot to mention: I made sure all numbers are stored on the SIM and not on the phone itself.

*** Edited to include update as of March 30, 2012 ***
Rogers resolved the problem!
I think they removed the old IMEI number attached to my Roger's cell number.
And I was told to remove any additional phone numbers stored to "My Settings>Phone Status>My Telephone Numbers". Problem solved!