It's not actually a bug, but rather a feature called Dynamic Availability:
http://Help.KVSTool.com/#Factors
Assuming your Agent is not located in the US, you can call
EK US Reservations to take advantage of the more favourable POS US Availability and book the Seat(s) you see via the
KVS Tool.
Thanks, this does make sense although my agent is in the US. No worries, Ill keep looking!
Thanks again.