1 - I create a task tracker with a select box field named "Completion"
2 - In this select box field, I create 2 values with the same name ("Done" for example)
3 - I create an artifact in my tracker and I set "Completion" to the first "Done" in the select box.
4 - When I search my tracker, everything works well:
- If I select the first "Done" value in my filter, the artifact is shown
- If I select the second "Done" value in my filter, the artifact is not shown.
5 - If I use a cardwall to see my tasks, using "Completion" as columns, my artifact appears in both "Done" columns. I think it is a bug as it should appears only in the first column.

Found on v5.11.99.17, not tested on other versions.