When importing quizes in the Bb6+ format moodle fails to correctly recognise the value of the correct answer for True/False questions, defaulting all correct answers to True. A comment in the code seems to assume that order determines the proper value, but the value is encoded in the xml. The following patch fixed the problem for me.

diff --git a/question/format/blackboard_6/format.php b/question/format/blackboard_6/format.php

index af27295..c935140 100644

— a/question/format/blackboard_6/format.php

+++ b/question/format/blackboard_6/format.php

@@ -525,7 +525,7 @@ function process_tf($quest, &$questions)

$question->name = $question->questiontext;

// first choice is true, second is false.

• if ($quest->responses[0]->fraction == 1) {

+ if ($quest->responses[0]>fraction == 1 && $quest>responses[0]->ident[0] == 'true')

else {