Compressor settings? 867 x 368 source to DVD

Can't seem to find the right Compressor settings to create an MPEG-2 asset for DVD creation.

My FCP source is 867 x 368, square pixels and I'm sending it to Compressor from FCP, but the conversion to rectangular pixels has me stumped. Even when I change my pixel aspect to NTSC-CCIR 601 / DV in FCP's Sequence Settings, Compressor distorts the aspect ratio further. I can't figure out what settings will retain my original 867 x 368, square pixel aspect without distortion. I'd like the Compressor output to be exactly like my 867 x 368 source, except letterboxed at top and bottom.

Anyone have the magic bullet?