If you have created songs with Scorecerer Pro before buying a license, the songs will have a trial watermark on them.
When you purchase and install your license, any new songs you create will not have the trial watermark on them. However, Scorecerer will not automatically create new unmarked versions of songs that have been previously created while in trial mode. This is a known problem that will be addressed in an upcoming update.
The workaround right now is to open each song from Scorecerer and then save it again. This will force Scorecerer to regenerate the images and, with your full license now installed, the watermark will be gone.