gruntjs - Using grunt's uglify on handlebars.js gives error

Question

I am trying to use uglify on handlebars along with some other files, but the minified file converts this:

[^\x00]*?

into

[^�]*?

So IE is having problems parsing this.

I read somewhere that it's a BOM issue. I tried this http://gruntjs.com/api/grunt.file#grunt.file.preservebom but that did not solve it. Any solutions?