The fix to the incredibly-small-name-column bug in nautilus has introduced a new bug. The name columns are often still too small, and they have to be resized even when reopening the same folder. At the moment it looks like this is going to be in Ubuntu Feisty to annoy me for the next six months.
I feel sure that the column sizes were remembered before. If not, I guess they just had better defaults before, and I guess that the name column resized with the window before so it was enough to just increase the window size, which was remembered.