Does the Push message still exist?

I am designing a Gnutella client and am trying to properly adhere to 
correct structure for all Gnutella messages. I am having a problem 
with the Push message. The message gets sent to firewalled servents 
but I never receive a response from them. I am using the raw 
ServentID and FileIndex values received from the queryhit message and 
sending them in my Push. I am also using the same TTL value that I 
use for my query messages.

In an attempt to look at other Push messages to see if my structure 
is wrong, I have temporarily programmed my client to notify me of all 
messages it sees that are not Ping, Pong, Query or QueryHit. I have 
noticed that no matter how long I run my servent program (in 
ultrapeer mode), there don't seem to be any other messages that come 
across. 

My question is this: Is the Push (0x40) message still in use today? 
If so, can anyone help me figure out why I can never get a servent to 
respond?  

Thanks in advance.

Bill