AVCHD to DVD - best project/rendering settings in Platinum 11?

Hello, this is my first post, but I've already picked up loads of useful info from this site.

I'm finally making the switch from SD (old Sony PDX10) to HD (Pana GH2, hacked). However, my output is entirely on DVDs for friends and family.

I have a mixture of footage from the GH2, e.g. 1080i (25 fps), 720p (50 fps), and I want to put it all in the same project in order to burn a PAL DVD. The thing is, I've noticed that I always end up with some jaggies or other artifacts like that when I create an avi file from the raw footage and also when I create an mpeg2 file too.

Does anyone have any idea what I need to do to avoid this? I've tried playing around with the interleave/blend settings, but it doesn't seem to make any difference.

Thanks in advance.

Matt