I don't know about 2007HE, but I installed the LCARS theme on 2006, and then decided to change it. I had to completely uninstall the theme, not just choose another theme. After uninstalling the theme and restarting, some elements of the LCARS theme still remained. I found that if I then changed the theme to one of the other included themes and restarted, the missing/unchanged elements returned to normal.

So basically, uninstal, restart, change theme, restart.

Hope it helps.