Update: you can find new video tutorials on how to install SnowLeopard on our new partner site technow.cc.
I just upgraded to version 10.5.7 of Leopard on my 1000H.
I did this by downloading the Combo Update directly from Apple (just to be sure‚Ä¶) and executing it on the eee PC.
Everything went fine, I just had to:
reinstall the modified graphics kexts in version 10.5.7
reinstall the Bluetooth kext from the Fixes folder
and strangely the PS2 kexts and to reapply the AboutThisMac.pkg
All of those kexts can be found in the 10.5.7 folder from the Install Package in this eNik article.