I usually have multiple tabs open in ie with a few different posts up. If I am reading one and go to log in to reply, after I login I get redirected to some other page I have open in another tab. It's a little annoying. It would be nice if it kept me on the same page where I clicked log in initially. So after successfully logging in I have to go find the thread again. Is this just me?
I was able to reproduce the issue you're facing. My guess is you're opening multiple windows and then logging in to one of them. At that point a cookie is set. If you then go to another screen which you initially opened you're actually logged in even though it doesn't display it. If you click on the login link it will then take you to the page you initially logged in at due to the cookie. I found two options you can choose from to prevent this from happening. On the second page, if you simply click on the refresh button rather than the login button you will stay on the same page and once it refreshes you'll be logged in. You can also login on the very first window you open and then on subsequent windows opened you should be logged in. Hope this resolves your problem. If it doesn't let me know.