The prophet Mohammed in Islam is seen with more reverence than Jesus in Christianity, invoking his name is also very delicate in Islam (you are supposed to say a blessing anytime you do and avoid invoking it lightly, there's a lot of rules around it).

With these religious/cultural differences I can understand how Muslim take greater offence to people making fun of their most prominent prophet as opposed to Christians, but also you have to take into account that because of that, people usually are more provocative with their humour when it comes to Mohammed.

I can't remember having seen any sexually depraved depiction of Jesus in mainstream media whereas I can clearly remember many that depicted Mohammed.

IMO it's not as easy to make fun of Islam/Mohammed because people tend to go for the extreme in term of dark humour but also it's not perceived the same way by the religious communities.