One Note can't open Sky Drive notes

[anlaoch]

HI.

I am trying to sync OneNote notebooks between my pc and skydrive. The notebooks were created using the web app on skydrive. They sync automatically with my Nokia Lumia 800. However, when I open a notebook in skydrive using the webapp and press the "open with OneNote" button, I get the following:

1. OneNote opens and trys to sync the notebook but I just get a red sync error symbol.

2. When I hover the mouse over the error symbol, it says "This notebook is not connected".

3. When I click the sync symbol and go to the errors tab, it says "OneNote cannot sync changes in this notebook because WebDAV support is not enabled on the web server (error code: 0x0000777).

I've already been advised to ensure the web client starts automatically, which I've done but still no joy.

I've attached a screenshot fwiw.

All help appreciated.