Problems on 3D Export Dialog

[CADAddict]

Hi,
I was trying to Export a 3D model to try the 3D PDF export plugin, and found that I can't select any export format on the dialog.
See the image below

I am using SketchUp 7 Pro, running on a Windows 7 Home Premium 64bit...
Anyone has a clue to why this happens? Any way to solve this?
Thanks guys!

[Gaieus]

What 3D PDF exporter plugin?

But anyhow, missing all the exporters is definitely a weird thing. Have you tried to reinstall SU?