How to copy AgileKeychain file?

I am using 1Password on a Mac (OS X 10.8.2). I want to copy the 1Password.agilekeychain file to a USB thumb drive, plug the USB thumb drive into my Windows 7 PC, then copy the file onto my PC. Then open 1Password on my PC and access the copied 1Password.agilekeychain file.

When I try to copy the 1Password.agilekeychain file from my Mac to the USD thumb drive, however, I get this message: "The Finder can’t complete the operation because some data in “1Password.agilekeychain” can’t be read or written. (Error code -36)". The 1Password app is closed when I attempt the copy.

Any ideas how to copy the file? Thx