Hi,
You are correct, when using any other prescaler than 1:1 one instructioncycle is not equal to one timer tick.

If you're using 1:8 prescaler then the timer is incremented every 8th instructioncycle but it still doesn't matter if the Fosc is 8kHz or 8Mhz, the relationship between instructioncylce and timertick/count is still the same and that relationship is the prescaler ratio.

The problem with the ASM-listing that is generated is that it's not "true" ASM, those commands you have in your listing are macros which you then need to "expand" into the "real" ASM instructions. (Did you really find those instruction in the datasheet?) But if it does work out to 8 instructions and your prescaler is 1:8 then it equals exactly 1 timer tick.

/Henrik.