You can use the single AO node that the wacro brings in. However, if you have anything set in the alt.diffuse/alt.specular channels, then unplug the relevant 'original' channel (diffuse or specular value). From the alt. diffuse/specular channel, plug into a maths function node. Set it to multiply, and add the nodes that were originally set to that alternate node into value one. Then set the AO node into value 2.

I hope that makes sense. If not, let me know, and I'll try and come up with seom screenshots later.

jonthecelt