Need help with blog address

Ugh, I hate to have to post for this, but I’m truely at a loss.

I recently added a couple of wordpress installs to my site, as I’m splitting up a joint blog. Installed in a couple of subdirectories, imported the blogs into a new database, and everything went smoothly.

I had set up a couple of subdomain pointers to those subdirectories, and decided this morning to try and make use of them, so I changed the wordpress address and blog address to the subdomain, rather than domain/folder. This, unfortunately, broke the blog; it would no longer display in my browser. I changed the URLs in options back to what they were, but if I try to access the blog, it now tries to point to the sudbomain/folder, which gets a 404, as that doesn’t exist (syntactically the same as domain/folder/folder, if my shorthand is hard to follow).

I’m confused. Is there something buried in my code that’s still trying to point to the subdomain?

For reference, the original site:
https://twoplayercoop.com/nick
The subdomain I tried to redirect to:
https://nick.twoplayercoop.com
What shows up since I changed back to the former:
https://nick.twoplayercoop.com/nick (404)

Any insight would be greatly appreciated.

EDIT: I’m also viewing this all exclusively in IE (all I’m allowed to use at work, unfortunately), so I wouldn’t be surprised if this is actually working fine, and it’s IE’s fault (I cleared cache, cookies, etc already). If it works fine in Firefox, Safari, et al, let me know. Thanks again in advance!

EDIT2: Worth noting: The blog will show up just fine if you go directly to https://twoplayercoop.com/nick/index.php… it’s just that auto redirect gumming up the works.