Hi! Im now going to try pre 1.8.1 Minecraft update to server.
Before you update do this:
Go to %appdata%, when you are there press ".minecraft" folder.
Then copy Bin folder, make new folder to you desktop and paste it there.
This is good, cause if we are going to back 1.7.3 on server you can just replace your new 1.8.1 bin with the old 1.7.3 version.
Lets hope that 1.8.1 is not buggy!