doctorjb,
To stop aa answering the Line Port you will need to take charge of the Line Port InboundCallRoute.
You need to make the change via the Obi Expert Configuration pages. From your OBi Dashboard, click on your OBi number and follow the prompts to get there. To change a value uncheck both boxes to the right of the value and leave them unchecked. After changing the values on one page, press submit at the bottom of the page and wait a few minutes for the Obi to reboot. Then move on to the next page if required.
Go to Physical Interfaces -> LINE Port -> InboundCallRoute
At the moment it probably looks something like this:
{(12345678912):aa},{ph}
Where 12345678912 is your cell phone number.
Remove the aa rule leaving this:
Physical Interfaces -> LINE Port -> InboundCallRoute: ph
As there is only one rule the {} is not required.
I trust this will restore your wife's happiness