Frame rate choppiness after deinterlacing

I captured to DV-AVI and it is heavily interlaced when viewing on PC (as expected). When previewing through software such as WMM and Nero ShotTime, however, the playback appears progressive (so I asssume deinterlacing is done in realtime), but the framerate appears just as I would expect. After encoding and deinterlacing however, playback is just not up to standard - it is choppy and seems more like a slideshow. On pause, the image looks as though two frames were mixed together.

Is there any way to emulate the far superior playback of DV-AVI through WMM and Nero after encoding. Resultant file size not too important. I would like the video to be progressive, though.

I have already tried encoding through VirtualDub and WMM.
Many thanks,

Deinterlacing varies. Try viewing your captured video with Powerdvd and see how it plays. Powerdvd and Windvd should show you playback as it would appear on your TV.