I have a problem with iMovie on iPad.
I didn't have enough space to export a project to the camera roll. And the iMovie export to camera roll functionality wasn't available.
For this reason I've made some space, and iMovie export correctly started, but just before to finish, I got the error message: "not enough space to export it" (although I've freed the necessary space).
But what it is worse is that now iMovie is using the space I've previously freed, and the app memory usage is getting bigger and bigger. And still the movie is not exported outside the app, I believe a new copy is cached in the app bundle after each (failed) export.
What can I do?
Best Answer
Not sure if you've found the solution or not, but discovered from this link: http://rockonflash.wordpress.com/2011/04/28/imovie-eating-memory-on-ipad/ indicated that if you make a change to the original project it frees up your space.
Additionally, I've read that it's better to save/export the project to iTunes instead of locally, and then distribute to where you need it.
Hope this helps you, or any other poor traveler who runs into this issue.