With your help I seem to get near the solution, but still it's weird...

with $a <=> $b I get

Anastacia
Springsteen
Laith al Deen
[download]

with $b <=> $a I get

Laith al Deen
Springsteen
Anastacia
[download]

there seems to be a kind of sense in the output, but it's still not sorted correct....(or the alphabet in my brain is mixed up)

I will work on it this evening an let you know about the solution (hope I find one), thanks for the input!

still pondering

Bjoern