Trouble "exporting movie" from iMovie when uploading to You Tube....

Hi, I have never had a problem with uploading my projects from iMovie to You Tube off my iPad. I have about 32GB's available on my iPad 3. I only have about 5 projects and never had any hassle going thru the upload process? Now, with my latest project complete (only about 4.5min) I click on upload to You Tube, it then says "exporting movie" as it normally says, but doesn't go any further - just hangs there?

Any help appreciated!