[Y_Less]

I would not recommend using your own encryption - even if it is truly one way. There are more things than that to consider, the most important one being collisions. A collision is where two different passwords give the same encrypted string - the more collisions there are the easier it is to break people's passwords - you may not know their password, but you know another one which gives the same result, so the fact that it's different doesn't matter. Just use known encryptions with known good profiles.

And read this:

http://forum.sa-mp.com/index.php?topic=78026.0

And I know why it goes wrong with numbers at least - you are replacing letters with numbers, you are then replacing numbers with other numbers, but this includes the numbers you have just inserted as replacements for the letters.