tbob - you are right - the DVD is a different program.
However the VHS version of the correct program is easily found, and anyway - if any governmental agency tried to stifle PBS content, they would scream bloody murder - you wouldn't have to comb non-mainstream sources to find out. The daily newshour program and the weekly presentations of Frontline and Bill Moyers attest to their independence and get far more viewership (though not alot) than would a WWI documentary on DVD. Hence, giving credence to such an attempt is not rational.