Was Season 1 used in Syndication much?

Maybe you simply didn't see the first season.

lol No i am not sure it wasd that. Like a lot of those shows -Mission Impossible, Ironside etc, they seemed to on tv on a fairly regular re-run basis for over a decade or so. But for the life of me i cannot remember Joe working for another firm.

I suspect that that season probably was not used in syndication as much as the last 7 seasons. The first season was indeed the "odd man out" because of Mannix working for Intertect, a detective agency that used all kinds of fancy gadgets (well, for 1967 -- tracking devices, computers, etc.) and had Joseph Campanella as Mannix' boss, Lew Wickersham. The remaining seasons had Mannix as a lone wolf detective working out of his combined home-office, with loyal "girl Friday" Peggy Fair. Given that Mannix typically refused to cooperate with Wickersham's directions, the producers probably realized that making him a solo practitioner was a more logical way to develop the character.

Because syndication means that individual television stations purchase the rights to the show, each station exercised a lot of independence in showing the episodes that they wanted -- as well as in how to edit the episodes to add more commercial time, often dropping whole scenes that they deemed unnecessary to plot. Some shows that were produced in the mid-1960s, for example, had both black and white and color episodes, and often when there were many seasons of the show, the seasons that shot in B&W didn't "make the cut" in syndication in the 1970s and later (e.g., Petticoat Junction and The Beverly Hillbillies). The same was true of the first season of Mission: Impossible, which had a different head of the IMF (Steven Hill instead of Peter Graves), so many stations didn't show that season, either. And the same was also true of the fourth season of Twilight Zone, which had hour-long episodes that didn't fit into the half-hour slot that could be used for the other four seasons' worth. So it wouldn't be surprising if you'd never seen the first season of Mannix when he was working for Wickersham and Peggy was nowhere to be seen -- you haven't suffered a memory lapse!

All of seasons 1 and 8, and 1/3 of season 7, were not included in the Mannix syndication packages. That is actually still true, to this day (see the "CBS Syndication Bible"). There is much speculation for why, to include limiting the number of episodes in a package to a one that local stations tended to like. (Series that ran only five seasons, for example, had something like the perfect number of episodes for syndication.) There is precedent for this in other long-running series, resulting in some "lost episodes." But, there is also precedent for including all of the episodes of long-running series in syndication packagess as well.

Since the decision was made long ago, the real reasons may never be known.

Undoubtedly, season 1 was not included because it would have confused some people to see Joe work for Intertect, then be out on his own, then work for Intertect again in the circular syndication cycle. But the reasons to exclude episodes from later seasons are less clear.

Suffice to say, Mannix fans were very excited when seasons 7 and 8 were finally released to DVD.

Curiously, season 1 was a very good season -- but the basic premise could not have lasted. How many times could Joe quit and come back while still appearing to be his own man? For other reasons as well, Joe became a much bigger character in later seasons.

For lots more discussion of Mannix, see the "Mannix is Coming!" thread on the Home Theatre Forum. And, as mentioned previously on this discussion board, there is also a new book on Mannix -- and not your typical TV log book.