WSUS 3 fails to download updates

I've been using WSUS 3 since its realease on our small
network (10 machines) with SBS 2003 with no problems
until about 3 weeks ago. In fact WSUS has downloaded and
processed over 20,000 updates!

Now periodically (every 7-10 days) I get the following
errors in my 2003 SBS Server Status update email:

364: WSUS file content download failed. The destination
file system vloume is not available. Verify that another
program, such as CheckDisk is not running to lock the
volume.

10032 the server is failing to download some updates.

Interstingly, chkdsk (as it has for months) was
scheduled to run 2 x's weekly as a task when this first
appeared I disabled it, but the error still happens.

If I REBOOT the server and manually run WSUS sync the
pending files are download.

I don't think this is a firewall BITS issue as when the
server reboots the files will download.

Is there something else that could lock the volume? If
so how would I figure it out? All other process run
without a problem. I do run Acronis Server Backup twice
weekly, but I've done that for years.

Thanks

In article <MPG.235bdb2f22fff5aa989744
@news.microsoft.com>, youare@somewhere.com says...
weekly, but I've done that for years.
>
> Thanks
>

Any help would be appreciated here.