Hi Lars,
I think you are right.
For a 20mer primer at 0.2 M Na-equivalents you can calculate a t1/2 of
approx. 3 sec. for annealing. And annealing time is should be short on
the LightCycler. More than 10 sec. makes no sense.
Read Wetmur JG, Crit Rev Biochem Mol Biol 1991, 26:227 for more.
Best regards
Nicolas