Crashing?
Then you might be able to rule out the client unless sometehing specific that send the data crashes you and he seems to be doing it more.
For example I know with packets that opening the spellbook without your backpack first will crash the client. Before the 4.0.0 clients it used one type of packets, and after it, it uses another. So it could be a case like this where he just tends to do what crashes him more then you.
Ask him to carefully record what he does before the crashes to see if you can find out whats causes it.
For example I know with packets that opening the spellbook without your backpack first will crash the client. Before the 4.0.0 clients it used one type of packets, and after it, it uses another. So it could be a case like this where he just tends to do what crashes him more then you.
Ask him to carefully record what he does before the crashes to see if you can find out whats causes it.