CsdProject with more than one SceneNode doesn't save correctly as a yncp

[NextinMono]

If a CsdProject with more than one SceneNode present under Root, it somehow saves something incorrectly that causes it to throw a "Attempted to read outside of stream" exception when reading CsdPackage.

Here is an example of such file, ui_playscreen.yncp is the one that works, and the copy is the same file but saved through SharpNeedle.
SharpneedleYNCPIssue.zip

If it can be of any help, I'm doing this to save the file:
WorkProject.Write(workProjectPath);