iMovie 08 export movie only 30fps

[house1999]

I am using a Sanyo HD1000 capturing 720p 60fps. Whenever I play the raw movies in Quicktime and bring up the inspector it shows that the movie is 59.94fps. I edited in iMovie 08 and exported using Quicktime h.264 and selected 60fps in the settings. However, when I go play the exported movie and view the inspector, the movie is only 30fps. I have tried all different encoders and the result is the same. Is this some kind of limitation with iMovie or Quicktime? Has anybody experienced this issue? Thank you.