[S4t3K]

I personally use sampGDK and it works correctly with this syntax :

pawn Code:

#include <sampgdk\a_players.h>

using sampgdk::logprintf;

#define AMX_DECLARE_NATIVE(native) \
            cell AMX_NATIVE_CALL native(AMX* amx, cell* params)

AMX_DECLARE_NATIVE(CheckUser)
{
      if(!IsPlayerConnected(params[1])) return logprintf("The user %d isn't connected !", params[1]), 1;
      char name[25];
      GetPlayerName(params[1], &name, 25);
      logprintf("This was printed from the Test plugin! Yay %s!", name);
      return 1;
}

Haven't ever used Invoke though, but it should be the same syntax (I think the problem comes from the fact you pass a variable where Invoke expects a pointer).