reinitialize the lcd, if the SD card is inserted or removed. It seems that LCDs can confused by electrical discharges from time to time.

Since a removal or insert of the sd card takes a long time in firmware, just reinitializing the lcd does not hurt.
actually, it solves a problem with the UltiControlle

Marlin/ultralcd.pde

 void lcd_init()
 {
   //beep();
+  
   byte Degree[8] =
   {
     B01100,
     {
       force_lcd_update=true;
       oldcardstatus=CARDINSERTED;
+      lcd_init(); // to maybe revive the lcd if static electricty killed it.
       //Serial.println("echo: SD CHANGE");
       if(CARDINSERTED)
       {