Why are there two imdb pages?

Not 100% on the accuracy of the information submitted and the episode counts, but if I'm remembering correctly...

It started on NBC as a made for TV Movie/Pilot Film (one entry)
NBC picked up the show for a season -12 episodes according to that board (2nd entry)
it was Canceled by NBC, and later revived in Syndication (Thus a 3rd Entry, and This very Board)

as to why these have yet to be amalgamated into one 'master-board' would be an issue for the IMDb people

although I would Imagine the switch to syndication and change in production Might have something to do with it... (I'd suggest looking into Baywatch, Mama's Family and Charles in Charge as points of reference as all 3 also began on NBC, before getting a longer life in syndication)