Links redirect to same-slug page in IE

So, I have a rather large site which I imported to wordpress. I am using the permalink structure: /%postname%/.html (using the handy ‘allow .html in pages’ plugin) to replicate the original url structure.

NOW…

Everything works fabulous in Chrome. However, in IE, say I have a link to:

/admissions/international.html

Here is the link code, in case you doubt me:

<a href="/admissions/international.html">International Students</a>

This link works in Chrome. I repeat.

In IE, it takes you to:

/faculty/vgroza/international.html

I can’t not have pages with the same slug name… we have over a thousand pages. I shudder to think how many are named ‘contact.html’…

Also, my first instinct was just to change the slug name, so I changed the second page to:

/faculty/vgroza/vinternational.html

Now the link to /admissions/international.html instead goes to
/academic/international.html !

The point is, I can’t just re-name the slugs so every one of our 1,500 pages is different. Why is it doing this in IE? Is there a ‘feature’ I can turn off that tells it to ignore your link and instead just scan for the first matching slug?