There is a bug in version 2.7. As I think reciprocal links should work this way:
* You may cross products to each other (turn on all checkboxes);
* You may choose one product and cross it to the second (turn on only first checkbox);
* You may choose one product and cross the second product to it (turn on only second checkbox).

The changes is very small, so minor version upgraded.

FULL PACKAGE. Update instructions included.

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