I am experiencing the same problem. For example, all I wanted to do was change the mount point for an existing ext3 partition (from /media/hda[n]) to root partition (/). When I clicked on Edit partition, the value in the field labeled "New parititon size in megabytes" was 0. If I only changed the mount point, ubiquity then wanted to resize the partition to 0.
I then canceled and re-launched Ubiquity and get the same behavior. Other partition types (swap, ntfs) appeared to be getting the size pre- filled in the field correctly. ** Attachment added: "/var/log/installer/debug" http://librarian.launchpad.net/6917669/debug -- Clicking "Edit Partition" shows wrong partition size https://launchpad.net/bugs/89509 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs