The difference between power43 and power44 is only in a different version of u-boot. If some whose system hangs with power44 can try with power43 (after flashing the stock kernel, as per Kieron instructions), run in xterm as root:

apt-get install kernel-power=2.6.28-maemo43 kernel-power-modules=2.6.28-maemo43 kernel-power-flasher=2.6.28-maemo43

And tell me if this version also hangs, it will help me in tracking the bug.