You guys need to do your market research. The vast majority of "global" players use Firefox or Chrome. Either fix it and get it to work with the browsers, or abandon the browser-launch platform. Unlike Korea, the entire population does not use Internet Explorer, and by adopting the browser-launch model in the West, you're simply asking for technical complications.
You are losing thousands of potential customers by making it such a hassle to even play the game - many will simply not go to the great lengths to try to fix a problem which inherently originates from your incompetence.