preview question capability wrongly denied to student who has moodle/question:manage capability

Using Moodle 1.8.4
In one of my courses I need to give students moodle/question:manage capability so they can author their own questions.
They can indeed access Questions from the Admin block, they can create and edit questions, but they are denied access to Preview questions, which is not logical.
Diagnostic: wrong test in file /question/preview.php lines 44 & seq.
// this might break things in the future
if (!isteacherinanycourse())

{ error('This page is for teachers only'); }

Whoever wrote that comment was right: it does break things for me!
I urgently need this to be fixed (simply remove the obnoxious lines) and committed to 1.8 STABLE, as I need it to work for my next class on Friday, Feb. 22nd. (our Admin accepts updating but is very reluctant to hack anything on our university moodle site).
Thanks,
Joseph