You need a Windows server to run the server-side scripts.
With UberScore Administrator you have control over many attributes of a high score list, including the number of scores returned, the sort order, and whether a user can submit multiple scores.
The encryption key in a server-side script must match the encryption key in the Flash High Score List movie clip. If the keys do not match, neither Flash nor the server-side script will correctly interpret the information.
Set the user's score to global space like this:
_global.score = currentScore
This must be done before the High Score List movie clip is reached.