Tmpg is the best transcoder. Give it a try. It has the highest quality and settings specifically for animations.

have no idea what the OP is trying to do and what he means by glitch.
IF you are rendering for DVDAPro video stream - then you may use the Sony MXF container which is holding a variant Mpeg2 codec and can be accepted by DVDAPro.

However a better delivery stream for efficiency, is just choose the Vegas template for Mpeg2 DVDArchitect video stream.

The animation is HD 24fps. I'm trying to render it to a format that can be used to create a DVD in DVD Architect or any other DVD creator. When I try to render to MPEG-2 (either the PAL widescreen or DVD Architect PAL preset) the rendered file stutters at certain points. I assume this is due to either a dropped frame or a frame not rendering correctly creating a "glitch" in an otherwise smoothly playing film. I'm not an expert so I can't offer an expert description of the problem. If I was an expert then I probably wouldn't need to post a thread like this asking for help.

In the past I've rendered about a dozen animations in the same format to PAL MPEG-2 without any problems so I'm trying to work out why, in this case, I can't do so. I also don't understand why the MXF file I rendered of the animation creates the same problem when I try to convert it to MPEG-2 in Vegas.

One problem you have is that your source is 24 fps and PAL is 25 fps. I suggest you speed up playback to 25 fps before rendering for DVD. The way(s) to do this have been discussed here many times.

A recent discussion of 24p/25p conversion...

...probably not the last discussion.