As I can see 30108 is ID of spell you cast, but debuff on target has different ID 233490. You can check "Show spell ID in tooltips" above spell list settings to see this by yourself.
Can you point me to the part of the code where it sets the duration as a number with a decimal?
if timeLeft < 10 then timeLeft = math_floor(timeLeft * 10 + 0.5)/10 else timeLeft = math_floor(timeLeft) end
Replace this with
timeLeft = math_floor(timeLeft)
Maybe I'll add settings for this someday.