User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0 (Beta/Release) Build ID: 20140212131424 Steps to reproduce: When using a combination of Mac OS X and Firefox 20 or above (for example Mac OS X 10.9 - Mavericks and Firefox 27.0) If a drop down list has more than 20 items, the scroll bar is meant to render to allow the user to see that there are additional values and to access them. SEE THIS LINK FOR FURTHER INFORMATION AND IMAGES: https://support.mozilla.org/en-US/questions/974370 1. Go to https://www.collect-art.com.au/apply/loan_application_form 2. Under 'Date of birth' select the day or year field - both fields have more than 20 values 3. The first 20 values can be seen, but there is no scroll bar to access the remaining values. 4. The keyboard can be used to access the remaining values - proving they are there - but not a suitable workaround as the user will not know the values are there. The issue occurs when CSS styles are applied and when they are not - proving that the issue is no related to CSS or HTML. The issue does not occur in Firefox 19 - proving it is not an operating system issue but an issue with the Mac OS version of Firefox 20 and above. Actual results: Drop down lists (select lists) are visually limited to 20 values, as expected, but no scroll bar is available to access the remaining values. Expected results: A scroll bar should have appeared where the lists have more than 20 values, allowing the user to scroll to the additional values and select them.

I have just tested Mac OS 10.8 - Mountain Lion with Firefox 27 and can confirm that the issue is still present - further emphasising that it's a browser issue - not the operating system or version of operating system. See attached image.

Dupe Bug 946571 ?

Yes.