HOOKING causes Delay?

[phthegreat]

HI,EveryBody!
I injected a dll into WOW.exe to read some data after file checking and before it connected to the game server.But after the dll modified the original code , it took a long time to connect to the game server.As I used OllyDbg to see why, I found that WOW.exe had been calling Sleep().Without the dll, WOW.EXE wouldn't sleep that long. How does it come and how to avoid it?
Many thanks!

[phthegreat]

Solved!I mistook the sequences of sending and recving data.