TOPIC: Discount code not working

Clients with Internet Explorer 8 are having issues with discount codes on my site (3.0.8a). I understand they don't work at all.

I have tried to emulate IE8 in IE11 using the in-built functionality but discount codes seem to work OK. But maybe this is not a reliable test.

If IE8 is the problem, do I need to fix DT Register or could this be a Joomla3 problem?

There are a lot of large organisations still running IE8 it seems ...

(I do need to upgrade to 3.0.9 but as I have some modified files (for cosmetic reasons) upgrading and testing is always a time-consuming exercise ...)

Thanks