Comment 2 for bug 557922

I have, exactly , the same problem. I can't install the kubuntu 10.04 x64 final version.
ubiquity version 2.2.24.

Traceback (most recent call last):
  File "/usr/lib/ubiquity/bin/ubiquity", line 524, in <module>
    main(oem_config)
  File "/usr/lib/ubiquity/bin/ubiquity", line 509, in main
    install(args[0], query=options.query)
  File "/usr/lib/ubiquity/bin/ubiquity", line 242, in install
    ret = wizard.run()
  File "/usr/lib/ubiquity/ubiquity/frontend/kde_ui.py", line 460, in run
    self.progress_loop()
  File "/usr/lib/ubiquity/ubiquity/frontend/kde_ui.py", line 863, in progress_loop
    (ret, realtb))
RuntimeError: Install failed with exit code 1
Traceback (most recent call last):
  File "/usr/share/ubiquity/install.py", line 2566, in <module>
    install.run()
  File "/usr/share/ubiquity/install.py", line 353, in run
    self.copy_all()
  File "/usr/share/ubiquity/install.py", line 685, in copy_all
    assert os.path.exists(fs_size), "Missing filesystem.size."
AssertionError: Missing filesystem.size.