South Park and others

In spite of most shows now being filmed in widescreen, why are several of them being shown as 4:3 on Freeview? Is this some sort of cost-cutting measure?

This shows I’ve noted that are doing this include:

TV2 – Two and a Half Men (only when repeated?), The Amazing Race, Tyra

TV3 – Project Runway, America’s Next Top Model, Models Of The Runway

C4 – South Park

Any other shows you know about where this is happening?