P2P can't work in all network configurations. most likely your mobile phone network is implementing a symmetric NAT. if the PC's wifi has a port-restricted cone NAT, then you could get P2P to work with another wifi (as long as it wasn't symmetric NAT), but it wouldn't work with a symmetric NAT.
please go to http://cc.rtmfp.net and post the results (minus your public IP address).
the results you're showing indicate a symmetric NAT (that is, a NAT that uses a different translation for each unique destination). there is no way for a peer behind a symmetric NAT to coordinate and find another peer that's behind a different symmetric NAT or behind a port-restricted cone NAT.
this posting by Matthew Kaufman explains the situation with NATs in more detail:
as far as "fixing" it: the issue isn't the protocol -- a symmetric NAT is inherently defective. the only fix is to not use a symmetric NAT in your network. unfortunately this is often outside your control (such as with your mobile provider).