I've managed to install the imovie 1.2 on iOS4.2.1.
i changed the Systemversion.Plist with ifile to system 4.3 (+string) reboot and installed it.
than changed the Plist back to old settings..reboot.
Funny thing is that the icon changed to white after i put back the old settings.
The problem is that i have a Wifi ipad and imovie 1.2 needs location setting to be set 'on' for imovie..otherwise it can't see in the local foto and movie library???
Does anyone know a workaround for this..?