aakk9999 - 5:42 pm on Jul 3, 2013 (gmt 0)
There should't be any reason to have the same page accessible via http and https.
But it does happen (and in fact it is not so rare). The main issue is because of the way how internal links are output in HTML - they are often relative or root-relative, rather than absolute.
This mean they "inherit" the protocol and domain name of the page they are linking out from - causing https pages to link to https version of the page that should remain http.