And I agree on earlier time - or even a Monday (7 or 8 p.m. - before Castle) or a Tuesday time.
Then again - it's like with "The Greatest American Hero" - they demand change, change things around (i.e. moving around the infamous storyline of one of the attendants shooting a nude layout, ergo breaking the flow), and even with decent viewership, just up and cancel it. The only difference here was Pan Am had the specific spot, whereas they killed "GAH" by moving it around too frequently. I still think part of that was due to the new producers hating SJC's idea of a superhero - this one dealing with the day to day issues with fewer "save the world" stuff.