We have experienced some problems with navigation arrows in SCORM player. Sometimes the arrow get disbled (see the attached file).
This is the package used in the test.
The test has been done with Moodle 2.4.3 (with FF20 and Chrome26).
In Moodle 2.2.1 it works fine, so does in SCORM Cloud.
The package has been creted with the new eXeLearning exported as SCORM 12. If the problem is in the package, please, let us know.