Description of problem: This is related to 817457. The 'select all' link should have a function that can undo select all such as "cancel" or "select all" link can changed to "Not select all" once it was clicked. This will be helpful, saving a lot of clicks on index across all the documents when users want to undo 'select all'.
Fixed in 1.7. Uncheck 'Select all' will deselect all. See https://github.com/zanata/zanata/commit/0f276b09d02b4f8148879bd1e4c620edaccd990a
VERIFIED with Zanata version 1.7-SNAPSHOT (20120708-0026) However, checking "Select all" will not check the "select all" in individual documents, which is describe as Bug 830006.