Getting a 'forbidden' message when trying to connect to my local site via Sitecore Rocks

Hi, very recently I've started getting an error: (403) Forbidden error message when trying to connect to my local development instance from Sitecore Rocks.

Every Google page I hit says that it's likely caused by the WebServices directory not having anonymous access enabled in IIS. However, it has.

The full error is:

 

The HTTP request was forbidden with client authentication scheme 'Anonymous'. The remote server returned an error: (403) Forbidden.

 

Can anyone please advise?

Mark