Meditate skill and mana regeneration rate bug?

[closedloop]

I have a level 40 cleric, with a meditation skill of 205.
every tick I receive 17 mana, then drops 1, and then jumps 17 mana on the next tick, giving me an effective regen rate of 16 mana per tick.

if I was at 0 mana the growth would look like this

second 0: 0 mana
second 6: 17 mana
second 8: 16 mana
second 12: 33 mana
second 14: 32 mana

ect....

after reading the meditate skill definition:

For every 12 points your Meditate skill has, you will regenerate +1 mana (per tick) when sitting.

204/12=17 +1 should equal 18 mana per tick.

is this skill working correctly?