SkyDrive Desktop App won’t sign in

The SkyDrive desktop app installed on my machine has worked fine for months, and all of a sudden it has stopped syncing. When I hover over the taskbar icon, it says that SkyDrive is not signed in.

Following some of the instructions in other forum posts, I uninstalled and reinstalled the desktop app. Still no luck.

I've taken a look at the error logs, and the same three lines keep popping up every few minutes:

09-14-13,17:16:52.939,168,448,0,AUTH,authplatformhttprequest.cpp(124),0,0,ERR,Request failed with status code of 500, marking as network error,

09-14-13,17:16:52.939,169,448,0,AUTH,oauthprofile.cpp(216),0,0,ERR,Failed making HTTP request: DRX_E_AUTH_NETWORK_ERROR,

09-14-13,17:16:52.940,16a,448,0,AUTH,authapi.cpp(477),0,0,ERR,Load profile properties failed : DRX_E_AUTH_NETWORK_ERROR,

My network connection is fine - I'm able to access the internet (as I'm posting this question, for instance), and I can access my SkyDrive files through the immersive app.

Any ideas how to fix this?

Thanks,

Andy