macro,
I ran into this and recently posted a question on TechNet about it. I included a link to your post here to show that what I was experiencing was not isolated. I also inlcuded links to all the posts that I could find on TechNet reporting something similar. One of those links is the post about the problem resolving itself. Here is the url for my post.
Windows 7 Access Server 2003 Shadow Copy?
A moderator on TechNet is researching it and I'm waiting to hear back. I think it would help if you chime in on that post.
I have a question for you. How do you have Shadow Copies set up on the server? Are the Shadow Copies located on the same volume as the files your copying or on a different volume?