I thought it’s the button that’s unclickable. Actually it’s the label that messes it up.

This one doesn’t work:

<button type=”submit” name=”signin” class=”button” id=”signinb”><label><span>Sign-In</span></label></button>

Workaround:

<button type=”submit” name=”signin” class=”button” id=”signinb”><p><span>Sign-In</span></p></button>