Netplay Help

I'm hosting a server on netplay right now trying to do CO-OP with my friend Nick. Now, I want to be Sonic and he wants to be Tails, but it wont let him change to Tails, and I can't change either. We're both stuck as Sonic. Then theres this one option that can change us both from Sonic to Tails to Knuckles. (that 0, 1, 2, and -0 or -1 option somehwere)
Help?

You most likely have forceskin enabled on your server. forceskin -1 turns off forceskin.