Titles can be very fluid. Movies were often released under different titles in the old days, and I have a couple of DVDs where the title on the print is different from the one on the case (I think
The Living Ghost is one). IMDB usually lists all the alternatives, but I have no idea how they choose the primary title. TV shows will change their titles, too, sometimes in mid-run (like
Enterprise becoming
Star Trek Enterprise [or was it
Star Trek: Enterprise?]) and sometimes in syndication (like some
Gunsmoke re-runs distributed under the title
Marshall Dillon). In casual conversation, titles are often changed or shortened. The "A" or "The" are frequently dropped, part of the title is often dropped ("
Star Trek" becomes "
Trek"), or just the initials used ("ST") or a nickname used ("TOS").
Probably not something to lose too much sleep over.