Think I'll drop Skydrive.  It seems to "get stuck" uploading a 20MB+ file.  The notification icon just sits at "processing".  It would be useful if this gave a little more information while handling particularly large files.
I fix this by closing the desktop (Skydrive) program, logging into Skydrive browser and dragging the file into the browser which provides a nice upload commentary and takes about 30mins.
Then I restart the desktop programme and -as expected - it says "up-to-date".

Thinking out loud...this is an email client (data) file.  I guess there's a possibility that it gets updated in a time which is LESS than the time it takes to upload it.  In this case, Skydrive would never catchup.  Is this a possible scenario?