It would seem that there is an issue when I 'sync' (to 'local') for files that contains a space character within their names; I'm guessing it's to do with the encoding of the space character and possibly the non-encoded comparison of names.
The 'local' files first get deleted, and then copied back again from 'remote'; it's a never ending cycle if you keep re-running the 'sync' operation:
NCH%20logo(1).jpg | 31 KiB | 1829.9 KiB/s | binary | 100%
NCH%20logo.jpg | 31 KiB | 251.7 KiB/s | binary | 100%
'E:\WebSites\TCS\Join\PYP\CmsFiles\Image\NCH%2520logo(1).jpg' deleted
'E:\WebSites\TCS\Join\PYP\CmsFiles\Image\NCH%2520logo.jpg' deleted
NCH%20logo(1).jpg | 31 KiB | 1829.9 KiB/s | binary | 100%
NCH%20logo.jpg | 31 KiB | 344.4 KiB/s | binary | 100%