I know this thread is over 18 months old, but i had, and luckily solved the Flip4Mac “unrendered” issue.
So for those who look here, like me, for an answer – here’s how you can get it working…
Simlpy place a blank text layer on a channel above your project. I imported a text movie from Livetype, copied and pasted in on to v2, rendered, exported and it worked. I imagine you could use the text tools native to FCP to do the same.
Hope it helps.
Ross