With SearchMyLibraryFirst off, and OpacAddMastheadLibrarPulldown on, logged in users are defaulted to their home library, regardless of the setting for "SearchMyLibraryFirst" The pulldown should honor the preference for "SearchMyLibraryFirst" and default to ALL if SMLF is OFF, and the patron's home library if SMLF is ON.
Patch from Ian Walls fixes this.
This should be fixed by the patch for 5390, please test
Tested, fixed.