Why does 74hc595 work "better" without GRND (pin 8) grounded?

Other Hardware LEDs and Multiplexing
33

Let's stop for a minute:
Try using SPI, see code for wiring:

#include <SPI.h>

/*
  Arduino       MAX7219
  SS     10     LOAD  12
  MOSI   11     DIN   1
  MISO   12     No Connection
  SCK    13     CLK   13
*/

const byte MAX7219_REG_NOOP        = 0x0;
const byte MAX7219_REG_DECODEMODE  = 0x9;
const byte MAX7219_REG_INTENSITY   = 0xA;
const byte MAX7219_REG_SCANLIMIT   = 0xB;
const byte MAX7219_REG_SHUTDOWN    = 0xC;
const byte MAX7219_REG_DISPLAYTEST = 0xF;

void sendByte (const byte reg, const byte data)
{
  digitalWrite (SS, LOW);  //
  SPI.transfer (reg);
  SPI.transfer (data);
  digitalWrite (SS, HIGH);
}

void setup ()
{
  SPI.begin ();
  //sendByte (MAX7219_REG_SCANLIMIT, ?);    //? = number of digits,  i.e. 1-8
  sendByte (MAX7219_REG_SCANLIMIT, 0);      // show 1 digits (zero relative i.e. 0=1 . . . 7=8)
  sendByte (MAX7219_REG_DECODEMODE, 0xFF);  // use digits (not bit patterns)
  sendByte (MAX7219_REG_DISPLAYTEST, 0);    // no display test
  sendByte (MAX7219_REG_INTENSITY, 7);      // character intensity: range: 0 to 15
  sendByte (MAX7219_REG_SHUTDOWN, 1);       // not in shutdown mode (ie. start it up)
}

void loop ()
{
  for (byte x = 0; x < 10; x++)
  {
    sendByte (0x1, x );
    delay(500);
  }

} // END of loop()

EDIT: updated sketch.