[AnnaSB]

pawn Code:

format(ServerInfo[NewestPlayer],32,"%s",GetName(playerid));

What... is GetName?
See, in C/++/PAWN you cannot directly return strings from functions, you should use pointers on arrays.
Use this instead:

pawn Code:

new NAME[24];
GetPlayerName(playerid, NAME, sizeof NAME);
format(ServerInfo[NewestPlayer],32,"%s",NAME);

Hope I helped ^^