OK found out the problem. It was just me being a plonker! Just for any other plonkers out there that might be as lazy as me, here is what happened.
I downloaded as3 and couldn't be bothered to download as2 and get the PlugIns folder from it's package to put into as3. Instead I actually used B54's PlugIns folder! Yes I know lazy and stupid and hence my weird no launching symptoms. I downloaded as2 and borrowed it's PlugIns folder and all is well with as3 now.
