air level spawn lag

I just made a Matrix unit defence like in starcraft, and all is well and everyone likes it BUT here is the problem. on every air spawn there is major lag. anyone know what could be a common cause for this? everything is great other then that :(

not sure but flying units tend to lag the game lot (especially the anti air perhaps, if there ar elightning towers it will lag

nope, it doesnt lag when they are being killd, just right when they spawn it freezes up till they all start moving.

well thats better then lagging a lot for a while, i think u can wait a few second for it to clear up.

:D