Answering my own post (sorry guys):
A wild stab at using german terms, E0.0 in stead of I0.0, worked.
Also, I must use A0.0 and not Q0.0.
My STEP7 is installed with english language. It looks like there is a slight oversight from Siemens here.
edit:
Thanks Walters, I didnt know there was a rewiring function in the Symbol editor as well.