Hi GMATassasin,
I'm not exactly sure how Business Schools in Singapore will individually view your IR score, but I can tell you that many Schools in the United States have publicly stated that an applicant's IR score is NOT a factor at all in the admissions process. As such, my guess is that you're probably fine. Since this is such a specific question though, you might want to post it in the Admissions Forum (on this site) - it's full of Experts there who should be able to offer up some insight. You can find it here:
ask-admission-consultants-124/GMAT assassins aren't born, they're made,
Rich
ps. that quote has nothing to do with your name - it's a motto of mine.