MeGUI can't detect interlacing (Anime source)

[me7]

I want to encode the South Park Season 11 NTSC DVD set to x264 with MeGUI. When analyzing the video for interlacing, the AviSynth script creator can't detect the video source type.
What now? Is there an alternative tool?

EDIT: I did check "source is anime"

[me7]

UPDATE: Here is the info from DGIndex. It says "Frame Type: Progressive" and "Coding Type: I" (which I guess means interlaced).

Can I use this to set the deinterlacing setting in MeGUI?

[me7]

UPDATE 2: I watched it frame-by-frame now and it looks to my eye like the following pattern: three pictures without visible interlacing, two obviously interlaced pictures, three without interlacing, two interlaced,...
Seems like a pulldown to me, but I'm not sure because my deinterlacing knowledge is very limited (see samples). Any suggestions?

[Nightshiver]

Why don't you post a sample video?

[me7]

I figured it out last night. It's 24 fps progressive turned to 30 fps via pulldown.
TIVTC with varying filed order does the trick, except for split screen scenes that have different interlacing timings (episode 'The Snuke' if you're a SP fan).
Is there a method for this as well?