He wasn't in ST4, that's why he isn't listed as being in it.

http://memory-alpha.org/wiki/Alex_Henteloff
http://www.ontariohst.ca/
No HST in Ontario.

Wow. I had the same reaction. I would have bet my life that was Stuart Pankin in ST:IV. I never even bothered to check the credits because there was no reason to since it was obviously Stuart Pankin, and not Alex Henteloff, who I had never heard of before. I'm now wondering if a number of the parts that I thought Pankin played back in the 1980s were in reality played by Henteloff? I just looked this guy up and he was a very active actor in the 1970s and '80s, but then his career seemed to come to a sudden end (for the most part) in the mid-1990s when he was only in his 50s. Ha, the guy should make a come back for roles where producers want the heavy Stuart Pankin, not the thin one!

Holy cow! For 24 years I've been so completely convinced that was Pankin, I never even checked the credits. I saw ST:IV three or four times in the theater, and I knew Pankin from "Not Necessarily The News", so I always just "knew" it was him.
Thank you for this thread. Not that I'm never wrong, but it's not often that I'm so badly mistaken about movie trivia especially for a movie and an actor that I know well (or thought I did!).

When I saw "Star Trek IV" in the theaters, I really did think that the portly guy with the glasses aiding Captain Kirk and co. was Stuart Pankin. Their bodies and voices were so alike. Then I looked for the actor's name at the end credits and I was wrong. It was one of those doubletakes where if I'm not careful, and I wasn't, I really would have believed it to be Stuart. Happy 64th, Stuart. Keep going.

User tb68gibbs279 posted in another topic that actor Alex Henteloff http://www.imdb.com/board/20378261/ looks similar to Stuart and is often mistaken for him. Hentelhoff's IMDB listing includes the Star Trek role.

was he the glass guy"Hello computer"