Since u deleted some parts of the sponsor with Spybot the uninstaller got cripled thats why it wasnt uninstalled properly.
To totally uninstall the sponsor:
1. Uninstall Plus!
2. reinstall Plus! with sponsor....
do not run spybot or any other ad-/spyware remover...
3. then uninstall Plus! again
4. reboot
5. reinstall Plus! without sponsor
Edit: welcome to the forum