How is Extreme Programming going so far

We've been having our 5-10 minute stands up. Good.

We've got stories and details documented well.  Good.

Developers are coming up with good estimates.  Good.

First iteration created and assignments made.  Good.

First iteration completed, 50% of stories not completed.  Bad. 

Why?  Nobody took the opportunity to mention other items that took their time away from the project during the 10 minute stand up.  So, make sure everyone knows this is their time to speak.  This is their time to say "I am swamped with support this week and will need more time or help with my tasks."

Secondly, once a developers signs up for a task, they become the "Project Manger" for that task and will follow it through to completion.  That means testing\customer sign off.