Someone asked that I post this. It's possible to stop Backup Assistant without rooting your phone.
Manage Applications :
At the top click ALL :
There are two running processes - Backup Assistant and Backup Assistant Client.
Click on Backup Assistant and press Force Stop.
Go back and then Click Backup Assistant Client and Press Force Stop (if possible).
Now it's not going to run.
If you make the mistake of going into your accounts and clicking backup assistant then you will need to repeat these steps.