IE11 border radius and border bug

Question

I have an odd visual bug in IE11 as you can see in image here >

_{(source: jonwallacedesign.biz)}

See the odd effect on corners of the white

Answer 1

Instead of a background-image why not use http://css3buttongenerator.com/ to recreate this button and save on any additional requests and loading time. I was able to re-create your button and your gradient just fine in IE 11 using the above generator. Picture attached; Button image