ACF Alps skin will overlap subnav items if it wraps
If there are a lot of items in the subnav list, causing it to wrap around, the next row will overlap the previous row. The skin is using inline layout for subnav. We can try inline-block, but would have to hack to make it work on all browsers.
(from redmine: issue id 651, created on 2011-05-19, closed on 2012-01-05)