I've created an XMPP chat client in python. Chat generally works except it seems that Google Talk 'blocks' some messages when sending from my chat client to a user using Google Talk. For example, if I send the same one word message 'hi' multiple times to gtalk user, it only displays it once. However, when sending that same sequence of messages to a user on iChat or on Adium, all of the 'hi's get shown. Sometimes, Google Talk also doesn't display the first 1-2 incoming messages from my client. 
Otherwise, chatting works. My client never has any trouble with incoming chats. Thoughts?
In case it helps anyone, I figured it out. You just need to specify an id attribute in each chat message. They can be random id's but each message should have a different one. I assume gtalk was 'blocking' repeated messages b/c it couldn't tell if the messages were distinct or just repeats without an id.
XMPP Chat Client - Some IM messages to Google Talk don't get received