Great Circle route difficulty

[BigBill]

I was brushing up on the procedure for figuring the great circle route, the one in the 50 year almanac by Kolbe and had some troubles. Maybe  I was just tired and the tv was on but 2 attempts at fairly close destinations, both under 400 NM just didn't work. Once I chose someplace more distant, about 2900 NM it worked fine. Is it possible to be too close to use? TIA