IIRC, the 70's Buck Rogers went through a couple changes in pre-production. It was going to be a miniseries, then they decided to make it a theatrical release. (It did well enough to warrant going ahead with the series.) If you've ever seen the movie, there are a few things too hot for network tv back then!

Sadly, the tamer, two part recut tv version with extra scenes isn't on the DVD set.

The Galactica pilot film was intended to be shown theatrically. (In Sensurround!) That's why there are two versions. Baltar is executed by the Cylons in the movie, yet he's spared in the tv series.