1) It's not just authors of books that aren't as careful with timelines as they should be.
2) If you want to play the game and assume that the TV show has no inconsistencies, then maybe:
a) Lois isn't well-versed with the horoscope and doesn't know her sign. (Admittedly, not likely, but possible)
b) Clark is mis-remembering when he interviewed with the DP. (I would consider this explanation highly implausible, given Clark's phenomenal memory and the importance of the interview to him.)
c) For whatever reason, Lois chose to lie to Star about her sign. This strikes me as the most likely of the three explanations. After all, it's not as if she hasn't ever lied before. Plus, she just met Star and doesn't know whether this apparently loopy new neighbour is trustworthy.
Or perhaps Tempus has messed with the timeline.
Joy,
Lynn
