when introduced delay in exploit?

[msairam at intoto.com (M.P.Sairam)]

I am a new to this exploiting and i am working on framework 2.7, if I 
introduce any delay in exploit script at the position after the 
exploit pattern is sent, how does it effect the exploit can any one 
please explain. I am Using backupexec_agent exploit as an example. If 
IPS is used then there will be some small delay in transmission of 
packets then if IPS buffers the packets which contain the URL's then 
exploit is not succeeding even though the IPS is not detecting the 
exploit, how can I overcome such cases?

Thanks ,
   ----
Sairam