How much data are you backing up ?
How long are you waiting fo rth backup to finish ?
It can take quite a long time to complete, ie from a few minutes to many hours depending on speed of your system(s) and amount of data.
This thread may be of interest
http://forums.contribs.org/index.php?topic=20072.msg78944#msg78944where it says
"Also have a look at your workstation share, after a minute or so you should see an empty file in a folder with the same number as your backup set, this file will gradually get bigger if you click on Refresh in Windows Explorer. If you see this then backup2ws is configured correctly and definitely working. Just be patient for it to finish."
Regards
Ray