try exporting the model froom the scene and making a new one...import. Delete prefs and start new scene...then save. I clear all temp history in WinXP.....failing that reboot the laptop...sometimes option 1 works so I dont have to do the rest.
Hope it sorts out
cheers bullet
bullet1968
"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes