strange extra spacing between checkboxes

Please see the attached PyQt4 program. It's a simple todo program I wrote. "Kartavya" means "Something that needs to be done" in Sanskrit.

I want to know why the spacing between the list items increases when items are added and how I can stop that from happening. The spacing between the list items must be constant whether there are items or not.

Thank you.

I think readLine() returns a line of text with a new line at the end. You might want to strip that newline - it might be causing the different spacing.