That usually happens. How many delays did we see with the Palisades line?
I don't remember. I remember it was announced series 1 would be released on may 5 2002, but then I think that was only referring to the first convention to sell them and they ended up released in june. After that it was said that the figures would not have any speciffic release dates, they'd just be released when they hit stores. I don't know if that counts as a delay or not, though the Muppet Labs playset was delayed.
Otherwise, the only delay I remember was for series 2, due to a dock strike which prevented action figures from being shipped. That was probably the longest and most painful wait between figure series, since the first series just came out and I had anxiously been awaiting more. I think the gap between series 6 and 7 was the only other gap to really strike a nerve.