Version: (using KDE 4.4.1) Installed from: Ubuntu Packages I use this feature regularly on Windows 7 at work and it's very nice to have.
I think you made a mistake here. This is not a kchart bug. I moved it to "kde" for now and you can move it to whatever you think is best.
Sorry the 'kchart' bit got cut off the category name when I selected it, I thought it was a more general category.
Manual sort mode allows this.