@K9999, since installing the "lock portrait mode" package I haven't noticed anymore system instability than before. Maemo has always been a little bit unstable for me (sometimes locking up when battery is low and/or the charger connection keeps connecting and disconnecting). Also, since I installed kernel power maybe like once every 2-3 weeks I get the "unexpected reboot: your custom kernel settings have not been loaded." Please note that my system automatically reboots everyday at 4am, which does seem to improve reliability.

Also, I don't really see how locking portrait mode would cause so many problems (other than cosmetic) if locking landscape mode doesn't.

Only issue I have left with locking portrait mode is maintaining portrait mode lock after rebooting. If someone knows how to make this happen please let me know!