ANSWER:

Really going out on a whim here but my traditional approach would be below. I don’t know whether it will work but it was too big for a comment, yet again it’s not a guaranteed fix. Let me know how it goes:

Replace the HTML with

#each modules}

    linkName}

/each}

Replace the CS with

Template.moduleHeader.isActive = () ->
    currentModule = this
    currentModuleName = currentModule.moduleName
    if currentModuleName is Session.get 'module'
        "class=active"

rickyduck from http://stackoverflow.com/questions/16538018