Comment 11 for bug 669459

The kernelparameter 'partman/alignment=cylinder' seems to fix this behaviour.

When you add the 'partman/alignment=cylinder' kernel-parameter before
starting the Linux installation, the partitioner will not realign the
extended partition to MB-boundaries and eCS LVM-info will be preserved.

So, installing Ubuntu 10.10 will go like this:
- Create the extended partition (and swap) with eCS MiniLVM
- Boot from the Ubuntu live CD
- Press a key to get the menu (this takes a second before being displayed)
- Choose your language
- Press F6
- Press ESC

Now you see the line with the kernel-parameters that looks something like this:
..... quiet splash --
Insert the partman-parameter, so the line reads like:
..... quiet splash partman/alignment=cylinder --

Double-check you spelled the parameter correctly.

Now proceed with the Linux installation.

Note: I have not tested this on non-Debian derived distro's.