Hopefully this helps:
1) Open EPDM Administration Tool
2) Select the User/Group
3) Settings (Bottom Left)
4) Reference Dialog
5) Untick "Try to check out all referenced files when the referencing file is checked out"
I have selected "auto select reference files to get latest when checking out" and "always work with the latest version of files." I've found while its slower to open, I've had less problems with people believing they were working on the latest version when a component of the assembly was not the latest.
Hope this helps!