ArcServe users?

Hello,

We have a Win2K3 server which performs a nightly tape backup using ArcServe 2000 Advanced Edition (v7.0). Since Wednesday, however, the backup has failed. After reviewing the activity log, I've determined that a single directory on another Win2K3 server is not getting backed up. The log shows EC, which I take to mean Exact Cause - correct me if I'm wrong, to be sharing violations.

Now, this makes me to wonder what would be causing this... this is a live server in a 24/7 company, so there are always files in use and some access problems are to be expected (they result in a 'unable to open file' warning, not errors like this), but this has been an abnormal amount, and I need to get this resolved. Does anyone know which users or services arcserve uses? Or what could cause this directory to magically lock like this? I'm doing a bit of a scramble here trying to get the backup system to normal operation...