Local sync & win7 homegroup issue - access denied from within Acronis to homegroup folder

Hi Folks - When I had online backup trial - I had setup 2 LOCAL syncs between a folder on my main pc (win7) & my local server (WHS 2011). it worked fine and still work fine.

Now I have no online backup(Trail ran out) & when I try to setup a new LOCAL SYNC with 2 folders... First on a Local HDD (Which it takes ok) & then a drive folder/drive accessible via homegroup - it gives me access error!!! It says windows cannot access \\xxx. you do not have permission to access \\xxx\documents - but I can access/edit/delete the files in the folder just fine from windows7. For some reason - Acronis true image thinks I have access problems even though there are no problems from within windows. What gives?

I read the new instructions on setting up local sync - and the new instructions say that the 2nd PC has to join the sync!!!. I never did this earlier. I have 3 copies of Acronis True image for each client in my home. However I dont have a copy for WHS 2011 as I did not think I need a copy of True image 2013 for the WHS just to get LOCAL SYNC to work. Do I need to have a copy of Acronis on each machine for a LOCAL Sync to work even though the drives/folder show up in Homegroup as a local drive/folder?

Thanks a lot for your help in advance, Any pointers will be helpful
Anay