I'm using the Jar from Sambuca's (
http://hob.dyndns.org/javamo/) , anyway i really think is not a MO problem.
Try to delete the Orbiter from the admin site, reload the router, wait for lmce to ask about your phone again, select Java Mobile Phone, go to Admin>Orbiter, select a correct screen size, (i added a Nokia5800 row in Size Table,i'm not at home and i don't remember the value,maybe u can try selecting 240x320 PDA to begin), Full Regen and Reload router.
This should work.
The touchscreen is ok, the only thing is i was not be able to use the entire screen of the phone, because the SO create a Directional Pad with 4 Buttons in the bottom of the screen, so the usable part of the screen is less than the 320x640 Display.