Comment 10 for bug 757720

I too have four primary partitions and had the some problem trying to install Lubuntu. In the end I tried ubuntu-10.10-netbook. It installed correctly, allowed me to allocate and format the extended partition (into / and /home), and once that was done I was able to install Lubuntu.

(Note that trying Natty kicked up the same "ubi-partman" error.)