Oddities with Browsers

I am having a few really big issues with browsers when logging into one of my wordpress sites. When I go to the main site it works fine in all browsers, but, when I try to login in firefox in the admin, by typing https://www.talkbeautyskincare.com/wp-admin, it redirects to this https://www.talkbeautyskincare.com/talkbeautyskincare/wp-admin and the error page comes up. The same things happens with wp-login page too. I’ve only seen this in firefox, not chrome, opera, or safari. I want to know if i’m the only one encountering this, or if I have some big issue.

Thanks.
Zach