Comment 8 for bug 201286

Pablo, please do not assign bugs directly to the Installer Team. We already get notified of new bugs for installer components, so it's unnecessary.

actionj317, if you boot the install CD, select a language, press F6 to bring up the extra options menu, then hit escape to remove it, it will give you a string of options that you can pass to the installer. Can you add partman/filter_mounted=false to it and let me know if that causes your disks to appear on the partitioning page?

To verify that you've added that option correctly, in the live environment open a terminal and type the following:
echo "GET partman/filter_mounted" | debconf-communicate

It should say "false".

Thanks!