Creating Notes for Non Project Entities

We have a Custom Non Project Entity in SG (Timesheets). We have given it the ability to Create Notes against it. From the Web Interface we can easily create notes without linking them to projects. However attempts to do the same thing via the API fail due to lack of project value. How can we make the API act similarly to the web interface and give us the ability to make Note entries that are NOT linked to a project. We would rather not use a generic project to services this needs. Furthermore we even attempted to create the note with a given project then attempted to remove the project and this also didn’t work. It should be noted that the original note we created in the web UI has no project value. Please Help.