The official lightscribe software is awful (in my opinion).
Are there any alternatives? (Windows 7)
Nero comes with a label designer of its own, supporting LightScribe and LabelFlash.
I'm not aware of any free alternatives, as these are proprietary technologies. There are most likely royalties to pay.
It appears that Nero is now offering a free version of Nero CoverDesigner, which is suppose to be able to print Lightscribe labels (that is what I used in the past).
You can download it here: http://www.nero.com/enu/downloads/
or more precisely: http://ftp6.nero.com/tools/Nero_CoverDesigner.zip
You still need the official Lightscribe System Software drivers from:
http://www.lightscribe.com/DownloadSection/windows/index.aspx
NOTE: I have not tried the current version myself yet because my Windows XP machine with the Lightscribe drive died in Superstorm Sandy and i am in the process of replacing it with a Windows 7 machine.