Unable to drag to manually sort reminders list in iCal

Hi and thanks in advance for your help.

I run Mac OS X 10.7.5.

I find myself unable to manually sort reminders in iCal by dragging them up or down. If I click on the text of the reminder or the checkbox, I am able to drag it anywhere but I can't "release it". If I release my click, it goes back to it's original position and doesn't bump the other reminder down the list. I hope I am making sense.

Can anyone help me?

Thanks!