Brasero won't honor speed settings in two situations:
(1) Selecting a non-working speed. For instance, a drive is only able to burn at 10x, 16x and 24x, and K3b is correctly showing this, BUT Brasero doesn't know the working speeds, as it *only* tests for the MAXIMUM speed, then it lists all the "theoretically possible" speeds down to zero, with a 2x step. So you'll have 52x-50x-...-24x-22x-20x-...-2x. If you select 24x, it will honor it. If you select 28x, it will disregard it and it will burn at the maximum speed, whatever that means.
Brasero won't honor speed settings in two situations:
(1) Selecting a non-working speed. For instance, a drive is only able to burn at 10x, 16x and 24x, and K3b is correctly showing this, BUT Brasero doesn't know the working speeds, as it *only* tests for the MAXIMUM speed, then it lists all the "theoretically possible" speeds down to zero, with a 2x step. So you'll have 52x-50x- ...-24x- 22x-20x- ...-2x. If you select 24x, it will honor it. If you select 28x, it will disregard it and it will burn at the maximum speed, whatever that means.
(2) Selecting a (bug) odd speed: 1x, 3x, 5x, etc. See upstream bug http:// bugzilla. gnome.org/ show_bug. cgi?id= 525501 in that case.