C&C zero hour multi play

Hello all I have a question.Me and my brother have C&C generals,zero hour on our pc's.We can play both of them 1 on 1 against each other fine. We added the destructive forces patch on both and ran it. We can play against each other however it is sloooowwwwww I mean like at a crawl.If I play by myself it works fine,if he plays by himself it works fine.Only when we play together against each other does it go slow as hell. Note- We can play the regular generals&zero together against each other no problem,it seems to only play at a crawl speed when we both play zero hour destructive forces against each other. Im confused because its obvious both computers can handle the game just fine,so I dont get why they both go so slow only when we play against each other on that Mod