If the prefab lower thirds do not work why not try making your own in a photoshop like program? By the way, I am curious as to what lower thirds on Vasst look like a 10 year old made them? Could you provide a link?
I've used several from the Editor's Toolkit's from Digital Juice. Animated and varied. You can check them out at www.digitaljuice.com.
By the way, I just checked and they have an end-of-the-month special for any toolkit for $99 (usually $399) - but this is only good until tommorrow (7/31). Killer deal!