World Upload Doesn't Work

Hello,

I've made a server and tried to upload the world. It says it works (and the checkmark appears), but when I log on, I see a regular world. I have double checked that I got the world right (by downloading it and checking it in single-player). The world works fine in single-player. I've already tried generating/re-uploading my world 4 or 5 times. Any ideas on how to fix it?

Thanks!

Also, I have multiverse installed and I'm trying to upload a world file to every one of the worlds.

Ok I will try that

It doesn't work. When I teleport to the co-ordinates spawn should be, I still see a normal (naturally generated) world.

Also, I have multiverse installed, and there is no generate button for any world except for the default world.