Disk properties in My Computer are opening twice

Steps to reproduce:

• Start Live CD
• Open "My Computer"
• Select a disk (either hard disk or CD drive)
• Open its properties (either with Alt+Enter or by context menu)
• Close Properties window (either with Esc, Alt+F4, or Cancel button)
• Expected: Properties window is closed
• Observed: Window closes and opens again (second time it closes properly)

Still happens in 0.4.15-dev-5224-g4572aad. Installation from Boot CD is affected as well, but it's quicker to reproduce with Live CD.

Nothing is logged in the debug log while the window is being opened or closed, but I'm attaching it anyway: 0.4.15-dev-5224-g4572aad.txt