If you try to install more packages than will fit on the disk, you get the 'need more space' dialog, but the amount needed doesn't like up with 'Space Needed', and it looks like this: Mount Point Space Needed / 582 M
If you click the OK- button on the window, telling you, that you need more space, the installer just hangs, nothing going on
The installer has actually crashed at this point. The bug has been fixed.