Apparently it's not possible to have both ODBC Native Clients 10.0 _and_ 11.0 installed simultaneously, at least not in 64 bit (they do coexist in 32 bit).
I had version 10.0 installed, as we work with sql 2008, but installed sql 2012 incl. its ODBC drivers to test a program.
What I didn't realize was that it automatically disabled my 10.0 driver.
Now I'm stuck with a 64 bit program that needs this specific driver to work.
I tried to reinstall 10.0 x64 from the 2008R2 installation media, but it errs saying that it can't as long as there's a newer version installed.
And uninstalling the 11.0 driver will ruin most of the sql 2012 installation it seems.
Has anyone experienced this, and found a plausible explanation for this non-coexistency ? And possibly found a way to have both drivers installed ??