Hi Jeanne,
Are you logging onto the user's machine with a local administrator account or a domain based account with administrator rights when the extraction works? I'd try logging on with an account that has identical rights of the user having issues and see if you experience the issue. If not, you know its based on the user's profile.
-David
Jeanne,
Windows 7 administration rights work much differently (at least it seems to me) than they used to. I think what you are seeing is the difference between Domain Administration and Local Admin. Obviously you don't want users having domain admin so you are going to need to figure out what the extraction wants.
I would suggest what David W. said. I also don't think it has much to do with Win 7 x64 as much as just Win 7. You might need to add a local execute on the database directory where the .dll is actually running from. I am shooting in the dark here cause I don't know your exact setup.
Feel free to reach out to me if you want to explain more details.
Thanks,
Dave Alton