ISboxer will send the next click you do to the windows you specified.

I have a similar setup and I sometimes hit my AOE macro key (for my druid or mage).

That means that 20 or 30 seconds later when I hit my autorun key (mouse 4 or 5) my mage and druid take off on their own. it's been annoying and I'm going to just unbind the key for them, but to answer your question.. those mouse clicks do get sent eventually, whenever your next mouse click happens.