SkyDrive syncs folders but NOT files

I was having problems with SkyDrive syncing files between the cloud, my two PCs and my Windows Phone.  Some files synced others didn't.

So I copied all my data off SkyDrive to local storage and then deleted all folders and all files in SkyDrive (using web access).

I now need to copy all that data back to SkyDrive and access it across my devices.  On web access (via https://skydrive.live.com/) I can't see a way of importing lots of folders with their files.  I can only see a single file upload.

So I went to the SkyDrive folder on my PC and copied all the folders & files their (simple drag & drop).  It all appeared to work.  I can see all the folders & files on that PC via windows explorer.

But:

• When I look on-line (https://skydrive.live.com/) all I get is the folder structure with no files within.  This is not a time issue as I've left it for a few hours - nothing.
• When I try to see the files via the Metro App it says something like, "Sorry there was a problem.  Please try again later".

I have spent hours reading this forum & other forms of on-line help.  I really need this sorted as I'm going away after the weekend to my University Residential School and my Tablet PC with SkyDrive access (OneNote, etc.) is crucial.

Please help.  Thank you in anticipation.

PS I'm running Windows 8.1 Preview on both my PC & Tablet PC.  I have Windows Phone 7.  I use Office 2013.