EDIT2: OK, I understand the other problem here.
Interesting. Yes, it does work with the 1=, but still bugs out without it. I'd say that was intended if the other link didn't work either.
It seems like the arguments are being passed correctly from the fix template, but the anchor template itself doesn't like it without the 1=? Take
{{Anchor|Follow [http://forums.guru3d.com/showpost.php?p=4936011&postcount=2444 this guide] under}}
Which gives: {{{1}}}
Now take:
{{Anchor|1=Follow [http://forums.guru3d.com/showpost.php?p=4936011&postcount=2444 this guide] under}}
Which gives: Follow this guide under
---
Currently all the anchor template is:
<span id="{{{2|{{{1}}}}}}">{{{1}}}</span>
It's literally including the entirety of the fixbox header as a span id for the anchor since we aren't passing a second argument to T:Anchor through T:Fixbox (I find this incredibly wasteful now that I think about it...). However, if there's a quotation mark in the anchor header (with or without 1=) it just puts an empty span tag there instead that I assume is put there by the wiki parser (I assume the intention was anchor fixbox headers, but having to anchor and reference it using the fixbox header text that useful?).
Quoation example:
{{Anchor|Quotation "killed" the span id}}
Which gives (note no span id): Quotation "killed" the span id
Which kills the span id in the full sentence, which made this response turn out weird before edits (again, no span id):
Follow this guide under the section "GeDoSaTo Setup" to create a driver profile for Final Fantasy XIII and enable the "AntiAliasing Fix" to fix block like artifacts on character hair