Comment 13 for bug 527848

the issue still persist. I was able to reproduce the issue using the daily-build from March 10th.

The error is the ubi-partman exit code 141. Then, in the syslog, it shows:

Device /dev/sda4 not found in os-prober output. as there are no OS installed on that partition.

When I ran the command

sudo os-prober

I only see the output shows:

/dev/sda1: ubuntu 9.04
/dev/sda3: ubutnu lucid

but not the /dev/sda4...

Hope this information help,