Intensity Pro - Deinterlacing in DirectShow

What is the best way to deinterlace video in DirectShow when using the Blackmagic WDM Capture filter? I am trying to display PAL video deinterlaced in an application however the filters I currently use to deinterlace it make the video start slow and jerky for several seconds. I assume there must be a better way!

Somehow I managed to get it to do the deinterlacing itself yesterday and it worked until I rebooted. Unfortunately I don't know how I did it!