How do you get the correct aspect ratio in your VCDs?

It seems that using MacMPEG2Decoder -> mov and then Cleaner 5-> mpeg one produces square pixels, which look fine on a computer monitor with the aspect ratio preserved.

However, when playing widescreen VCDs, the pixels are not square but slighlty taller than wide. This produces an aspect ratio that make the picture look taller that it should, i.e. people have long faces, which look like crap.

A played around with the settings in Cleaner 5 but the resulting MPEG1 file is always the same with the aspect ratio not correct on the VCD disc.

Is this a problem with stand alone VCD players or can it be corrected in the conversion tp MPEG1 process?