I don't think I have any answers for you unless somebody else on the forum can add anything. Perhaps try stopping iTunes before you open LW & re-open it after. Which version LW do you have? Sorry!
I know just a little abou iMacs but nothing about eMacs. The early-mid history iMacs didn't have much in the way of graphic card support, meaning much of the sudden stress & strain of some apps fell directly upon the RAM & CPU. This could be an issue you might have to live with, but try to find a way to accomodate both somehow.