Disabling "Next" doesn't work when there's a Timing question in the same page.

Hey,
I'm trying to disable the "Next" button for one of the questions in my survey, so that I can later re-enable it once a condition is met.
This usually does the job:
Qualtrics.SurveyEngine.addOnload(function()
{
this.disableNextButton();
});
Unfortunately, when a timing question is included in the same page (i.e. no page break between the question and the timing question). Disabling the next button doesn't work. However, the timing question must be in the same page in order to time and count the clicks for the regular question ...
I also tried:

• Using jQuery to disable the button, i.e. jQuery('#NextButton').attr('disabled', true)


• Adding the disable code to the Javascript of the Timing question.