You need QuickTime 7 installed (not QuickTime X) to import QuickTime files in Premiere Pro.
See this page:
That page was written for After Effects, but the same information applies to Premiere Pro.
I don't think that can be it; I don't have any problem getting any other clips from my camera into Premiere, just these ones. I've got QT7 as well as QTX too.
You can modify and save movies out of QuickTime if you have QuickTime Pro installed. (It's a useful utility for only $29.95, I think.) Try doing that.
Actually, even before that, try opening the movies in Adobe Media Encoder.