Exporting HD movie using Quicktime Conversion

I am having problems getting good quality movies from my edited AVCHD camera files. What I want is to get exported clips as MP4 movies at 1080i, (60 fields per second). I use both FCE "Export using QuickTime conversion" and MPEG streamclip (with AIC files as source). From FCE I use the H.264 compressor, and from streamclip I can choose either H.264 or Apple MP4 compressors.

I want to feed the TV 1080i so that the deinterlacing is done by the TV. I use WD TV Live media player and a Sony BDP-S370 to play the files.

When using the WD TV Live I set the output to 1080i/60Hz. When I play the clips, about 50% of the time I get an excellent result: smooth motion, clean edges on moving object. The other 50% of the time there is severe double-image at the moving edges. By pausing and resuming, the playback changes from the "good" mode to the "bad" or vice-versa. This happens regardless of which file I use (FCE, Streamclip H.264 or Apple MP4).

When using the Sony Blu-Ray player, the Streamclip Apple MP4 compressor show the same effect, but the H.264 files are consistent, but show soft edges.

Here is what a "good" image looks like:
http://yfrog.com/fvimg15450j

Examples of the double-edges:
http://yfrog.com/2fimg1548fj
http://yfrog.com/bcimg1549vj
http://yfrog.com/04img1550yj

(Note: the above are taken from still-frame images on the TV. When played, the double images jitter>)

I have been in contact with WD support about this, but I'm not sure it is their problem since a similar thing happens on the Sony.

Details of my export setup can be found here:
http://yfrog.com/31fceqtexportp