[X4U] Video questions

[Robert]

I have a Sony HDR-SR12 AVCHD camcorder. Bringing the files into iMovie  
they play great. I then burn them onto a Blu-ray disk using toast  
9.0.2 They play back great except every so often I get a pause for a  
second and then the movie keeps going. Tried shutting chapter markers  
off but that didn't help. This is a little annoying. Using iMovie I  
have exported the files into quicktime using mp4, setting being 1920  
by 1080 at both 15 fps and custom 30fps.  Both looked terrible. So  
question is what settings should I be using to get the best results on  
a blu-ray disk. It would be nice to be able to go from iMovie to toast  
directly. I have a MacPro, 5 gb ram, 10.5.3 and toast 9.0.2.
Thanks Bob