I've had this before, but can't seem to replicate the steps I did back then. I've got an Umbraco 4.5.2. site which is running on port 8084 in a development-environment. All works well.
When I want to publish the website to the production server, the umbraco-backend seems to want to keep using the port 8084 and therefor my backend (starting at login) is really strange. Can't seem to update any content (or anything else for that matter).
Now, I assume, it has something to do with caching of sorts, but what setting to change (or what to delete)?
This is my login-screen (no red border on erronous login)
And this is my back-end (there is content - i can see content in the front-end - just not visible in the content-tree);
This is my back-end on the development machine (did nothing but crude copy and edited the database connectionstring to match my production database).