Mapbox.js/leaflet.js working in IE but not in FF

[hoge6b01]

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I am a noob writing leaflet/Mapbox code.

I got a map with the following code. Works like charm in FF but cannot see anything in IE. Maybe it is just a comma error like here?

This issue just came on as I added leaflet-osm. Just then IE startet do refuse work.

Hopefully someone can have a look and point out, what's the error. Thanks

You can find the code here:
http://gis.stackexchange.com/questions/124551/mapbox-js-leaflet-js-working-in-ie-but-not-in-ff