Mixed 720P & 1080i in same project.
 

I have a CS4 project which includes mixed format footage, 720x50P, 1280x1080x50i and 1440x1080x50i.
I usually keep to one flavour so making an MPEG2 for DVD is no problem, it's either progressive or interlaced but with this mixture should I interlace the progressive footage or deintelace the interlaced before I make and MPEG2?