maemo.org - Talk - Submenu in Maemo SDK disappears quickly

I tried to install a development environment for Nokia 770. Everything looked fine. Xephyr started, Maemo UI appeared in Xephyr window. But when I clicked on the Taskbar on the left side, the menu with "Web, Contacts, Tools, Games, Extras" showed up, then clicked on one of them, the submenu showed up and disappeared very quickly. You won't get a chance to click on the submenu.

I searched internet. Only thing I can find is "Submenu has problem in some systems" in Maemo2.2 SDK release notes.

Does anyone has same problem as I had? Is this the problem mentioned in the release notes?
If you have same problem, how do you get around of it?

My system:
AMD X2 TL-50,
Ubuntu 7.04 64 bits
Scratchbox 1.0 R4
Xephyr running outside Scratchbox
Scratchbox' target: i386 (PC)
Maemo SDK: 2.2 (i386)

I've tried Maemo 2.0 with Scratchbox 0.9.8 and found same problem.
Haven't tried Maemo 3.0+ yet.