[Note: The first part of this entry is an excerpt from a mail in response to a note that there seems to be a continuity error in SoS, concerning the date of the death of the outlaw Simon Toyne and Rhaegar's defeat of him at the tourney at Storm's End, as reported by Ser Barristan early in the book and as recorded in The White Book.]
Ooops. Good catch...
As to this glitch... I think my defense in that the account in The White Book is correct. Ser Barristan is an old man, after all, recounting things that happened in his youth. You ought to see me and my friends sitting around at a con:
ME: Hey, remember Torcon 2, when Joe Haldeman found two naked girls in a bathtub of grape jello. Alice and Angela, wasn't it?
SOMEONE ELSE: It was lime jello, you idiot, and it was Big Mac, not Torcon. Three were three girls -- Betty, Veronica, and Lee.
JOE: Lime jello, two girls, it was Applesusan and Avedon, and it was Discon.
In other words, Ser Barristan is undoubtingly conflating events that happened at two or three different tourneys. Any way, that's my story and I'm sticking to it.
[On a more humorous note, the analogy GRRM uses refers to an actual event. After I suggested I should really get to a con if naked girls in bathtubs of jello was a common feature, he replied: "You're twenty years too late. It happened in 1974. Fandom was livelier then... well, it was still the 60s..."]
On another minor inconsistency, someone on the message boards (Moreta) noted that Tyrion describes Dancy as being a honey blonde to Oberyn (p.437-438). She's a redhead in CoK, though. Maybe the honey blonde is the girl named Jayde, in the appendix of SoS? She was only mentioned once, by Anguy the Archer in one of Arya's chapters.
Maybe Dancy dyed her hair? If Daario can have a blue beard and Greenbeard a green one, going from redhead to blonde shouldn't be too hard.