My solution was to quit U1 via the system area app icon and restart it via the desktop icon. It then carried out the sync operation, but it didn't update the space used! So I quit again the same way and restarted it, then the usage updated.
How can I recommend this product choice to family, friends, colleagues or customers when it needs this much baby sitting? Sure I could have carried out the other suggestions above (shutting down and restarting services), but the average Joe isn't going to be able to do that easily without clear instruction -- heck some people can't even understand how to create a new folder to store files...
Thanks for the tip dokoma. It worked for me!!!
The folder in WIn7 for me was
After deleting the files in this folder and restarting U1 everything worked fine. You'll lose your sync directories. Delete it via the U1 Homepage and reset it again.
Thx and BR