Why can't I get AVCHD to look as good in FCP7 as direct output from camera

I've been comparing my Sony HDR-SR12 footage and noticed a problem after import with FCP and other Mac apps.

Quality issue:

items in motion not as clear/smooth in FCP and subsequet exports as it is directly from to monitor OR files opened in Windows with media player. It is not very noticable until you project it on a 100 screen or play in full screen on an imac.

• it is most noticable with scenic landscape pans..even slowly. Items moving across screen have a slightly strobed or choppy/blur effect that make it difficult to focus on them. Again.. NOT a problem directly from camcorder to projector/montior or playback on Windows media player, so it's not the camera file.
• exporting to quicktime doesn't help, so it is not likely a processor/disk speed issue on playback.

Sony file spec: AVCHD 1440X108060i 29.97fps

Camera output- mini HDMI-(monitor), USB(file transfer).

What I have tried.

• OS 10.6.8 with FCP7- import AVCHD files with pro res 422 codec. Timeline auto prompt switched to proper setting. Still no improvement- I then changed setting for lower/upper field, etc. No difference.
• iSkysoft AVCHD/MTS converter- playback in quick time- still no improvement.
• Booted in Windows- converted AVCHD files to WMV- inital trial not any better, plus other resolution/qaulity issues.

I have an iMac 2.8Ghz intel core i7, 8gig ram and 7200speed internal HD.

Anybody out there have similar problems?

thanks!