Wouldn't the black frames be a result of a "slug" or leader spliced into the film? Back in the late 80's and early 90's I think this was a common practice since actual film prints were used for broadcast. Now, though, broadcast standards for b&w material have become much more strict and everything is cleaned and prepackaged on analogue/digital video anyway! So, while there may be no excusing it, the black frames really are less jarring than a broken image that may appear to slide off your screen or show sprocket holes and, most importantly, it is a quick, down-and-dirty cover-up for severe picture damage in broadcast prints.
I have off-air recordings of at least ten or more Stooge shorts that have the black frames, including Brideless Groom, Three Little Beers and Three Pests in a Mess. All are from the supposed re-masters shown on Ted Turner's WTBS around 1992-93.