We would need to see a Fiddler trace to troubleshoot plays not uploading from the software; we don't have a systemic problem in this area right now.
Here are instructions for downloading and installing Fiddler: http://forums.zune.net/281039/ShowPost.aspx
Once you have the trace, you can create a report here: https://connect.microsoft.com/zune?wa=wsignin1.0
Jessica Zahn, Zune Social Program Manager ~ This posting is provided as-is with no warranties, and confers no rights.