How did you delete C2lop?
Spybot Search and Destroy click here can remove most variants of lop/Toolbar. Recent versions of Ad-Aware click here can remove most variants of lop/Toolbar; both programs are free.
There is also an uninstall feature in Lop which can usually be found on the round icon in the system tray. To do so: Click the right button on it and choose 'Menu'; on the resulting window, click 'Help', then 'Uninstall'; at this point the lop/IMZ variant will (annoying) ask for a number to be entered to confirm.