iMovie 10.0.9 will only share (to file) 1m 53s of a 22m video

I have a 22 minute video I've put together in iMovie. Its made up of two clips and a couple titles & transitions. Nothing strange or "over the top produced". It plays fine withIN iMovie and tells me it's final length will be 22 minutes and a final file size of 1.2GB. Last night it would render 3:06 of 22:02. This morning it will only render 01.:53 of 22:02. I've not yet successfully rendered the entire movie.

I'm running OS X Yosemite Version 10.10.5, Macbook Pro, 2.5GHz Intel Core 2 Duo, 4 GB ram with about 150GB of hard drive space available. It worked on my last project which was 15 minutes in length (forget the final file size). Any thoughts ??

Thanks - RJ