I decided to try fiddling with the new list editor for kicks and giggles, so I entered a title and a description, then I selected Section 1, gave it a name, and hit enter to create a new section.
It created a new section, but before I could finish naming it, I got a refresh of the page, with the title and description unchanged, one section (Section 1), and a red error message up top:
Sects
This field is required.
My guess is that the enter key is creating a new section and trying to create the list at the same time, so it comes up with an error because the second section title isn't finalized. I was able to get around this problem by avoiding the enter key when manipulating the sections. I guess the logical solution would be to unbind the enter key from the "make list" function, if that's possible.
Oh, and I'm using Chrome 5.0.375.70 beta on Win 7 64-bit Home Premium, if any of that makes a difference.