This is particularly directed at @Celsh because it is directly related to the Elemental Shaman rotation we talked about previously, but I am posting the question here for everyone's input in case people have different tweaks/solutions.
I've been working on my rotation over the past few days in preparation for the possibility of switching to my shaman as my main character, and I've noticed something odd that is compounded by the discussion we had last week about Active Time. As I proceed through my rotation, I get to a point where I need to use my filler spell (Lightning Bolt). I normally start spamming the key after the previous spell begins to cast (or casts if it's an instant), and generally the spell I'm spamming starts instantly. But I've noticed a weird delay or lag often when I switch to Lightning Bolt. The previous spell is done, so it's not waiting for that, and I've checked a few times to ensure it's not a mana issue. Sometimes, I'll spam the key for a good 2-3 seconds before the spell starts to cast. And it seems to happen mainly on that one spell. I've noticed a bit of a delay on my Warlock as well, but nothing like this.
Is this normal? Am I doing something wrong? Any thoughts?