Hello i'm the author of http://wow.curse.com/downloads/wow-addons/details/magemanabar.aspx
It seems that whenever OmniCC detect Cooldown frames, it add a timer over it. So far it's a pretty clever method.

Unfortunately i already have a built in timer in my addon, which lead to have two timers for one cooldown. Do you have any method i could implement to prevent OmniCC from adding a timer over my Cooldowns ?

Of Course i could add an option to disable my timers but there is some place i don't want any timers at all and in this case my options wouldn't work.

Apply this flag to each cooldown model:
noCooldownCount = true

Then, call this method:
OmniCC.Timer:ForAll('UpdateShown')

mmmh thanks but then i don't know how to apply this flag. Yes i'm using XML for building the frame but creating Cooldown ones in Lua using :

    CreateFrame("Cooldown","MMBevocationCooldown",MMBevocationFrame)
    MMBevocationCooldown:SetAllPoints(MMBevocationFrame)

And when i should i call your method ? after having created the cooldown frames ? and do i have to do it only once per session ?
anyway thanks for your fast anwser.

someone gave me a solution on #wowuidev
adding myframecoodlown.noCooldownCount = true in lua did the trick.