The only text that really makes me wonder if Castle Black has moved is the fact that it is south of Dzur Mountain when raised, but the "tip" can be seen to the east 240 years later.
Unfortunately, I'm not entirely sure what the "tip" is. If it's the leading edge of the mountain's foot, Dzur Mountain could be northeast of Castle Black, which satisfies both quotes. Sethra's lair being more north than east, but the mountain extends far enough south to be more east than north of Castle Black.
The main reason I don't think it has moved is because no one says it has. At no point does Vlad mention it moving, which is the sort of detail I'd expect from him.
If it has moved, I'd say that movement took place between The Lord of Castle Black and Taltos. Even if I accept this is true, and exclude the information in The Lord of Castle Black when trying to locate Castle Black in "Vlad's Time", there is enough information in the other novels to pinpoint its location fairly precisely.
However, based on the text referenced above, I do not see any indication it actually has moved, so I will go forward under the assumption it has essentially remained in the same location (or always returned to the original site) for the last 240 years.
Questions? Comments? Please contact me at dragaera [at] bryann.net.
Copyright © 2010 Bryan Newell, unless otherwise noted.