When satellites are near the pole, they occasionally develop a glitch in the footprint. The attached picture illustrates this behaviour.The glitch is a spike from near the lowest (magnitude) latitude point towards the pole.
This appears to occur from two different tests being applied for determining if the satellite coverage extends over the pole. The first is the test beta>pio2-ssplat. The second appears when pole_is_covered. When these disagree, odd artifacts can occur.
An initial replacement of the the test beta>pio2-ssplat with pole is covered yielded artifacts.
This testing occured with the AO-51 tle with the epoch 2011 November 13 03:28:31.