Gary Riley and Dean Cameron
I heard they had some personality clashes on set. Cameron was a hardcore Libertarian and Riley was just starting to into the whole hippie thing (he got deep into that lifestyle right after this). Riley has now become more of a neohippie type (I think?).
According to the director of Bad Dreams (1988), Cameron didn't get along with Taryn from Dream Warriors either. I'd bet it was for a similar reason.
I think Cameron has mellowed somewhat since then (I think?).