Some of these NLE's don't play well with the high bitrate mts files (AVCHD wrapped H.264 codec) straight out of the camera. You might want to look into transcoding with 5DtoRGB, Cineform Neoscene, or some other software that will convert the footage to a more easily workable intermediate lossless codec. I know the first two I mentioned can also do a bit of chroma upscaling of the 8 bit camera files to 10 bit 4:2:2 or even 4:4:4. It'll smooth a bit of the ugly 8 bit color banding in the process.

These intermediate codecs may take up more storage space, but require less computing horsepower to deal with. Then you can re-compress your final product to whatever delivery codec is required for your project.

Search for "GH2 workflow" and you'll pull up some similar topics.

So it's final cut that's the problem then? (with spanned files)

@Rodrigo If you're using a Mac with Final Cut, I find it works better to first copy the media off the card as a single archive (don't try to ingest directly from the card), then use Clipwrap to convert the MTS files onto a separate volume (where my Final Cut events will live.) When you import, just mark the checkbox so it won't copy into the Events folder, and of course transcode to an LT version to make editing easier. This workflow seems to work fine with me using FM 2.02, and I just finished shooting a couple of hours of footage without issues.

I'm using Class 10 cards rated at 45 Mbps and 90 Mbps.