Hi Serge.
Please have the code of a working program with the TFT and Mega (it's running right now for checking).
It is the standard test program with the definition as per my previous post.
Next I'll post the libraries configuration.
In this way the TFT works, in any other test I did it didn't.
Hope this helps. 
Ciao. Aldo
// UTFT_Demo_320x240
// Copyright (C)2015 Rinky-Dink Electronics, Henning Karlsen. All right reserved
// web: http://www.RinkyDinkElectronics.com/
//
// This program is a demo of how to use most of the functions
// of the library with a supported display modules.
//
// This demo was made for modules with a screen resolution
// of 320x240 pixels.
//
// This program requires the UTFT library.
//
#include <UTFT.h>
// Declare which fonts we will be using
extern uint8_t SmallFont[];
// Set the pins to the correct ones for your development shield
// ------------------------------------------------------------
// Arduino Uno / 2009:
// -------------------
// Standard Arduino Uno/2009 shield : <display model>,A5,A4,A3,A2
// DisplayModule Arduino Uno TFT shield : <display model>,A5,A4,A3,A2
//
// Arduino Mega:
// -------------------
// Standard Arduino Mega/Due shield : <display model>,38,39,40,41
// CTE TFT LCD/SD Shield for Arduino Mega : <display model>,38,39,40,41
//
// Remember to change the model parameter to suit your display module!
UTFT myGLCD(CTE32_R2,38,39,40,41);
void setup()
{
randomSeed(analogRead(0));
// Setup the LCD
myGLCD.InitLCD();
myGLCD.setFont(SmallFont);
}
void loop()
{
int buf[318];
int x, x2;
int y, y2;
int r;
// Clear the screen and draw the frame
myGLCD.clrScr();
myGLCD.setColor(255, 0, 0);
myGLCD.fillRect(0, 0, 319, 13);
myGLCD.setColor(64, 64, 64);
myGLCD.fillRect(0, 226, 319, 239);
myGLCD.setColor(255, 255, 255);
myGLCD.setBackColor(255, 0, 0);
myGLCD.print("* Universal Color TFT Display Library *", CENTER, 1);
myGLCD.setBackColor(64, 64, 64);
myGLCD.setColor(255,255,0);
myGLCD.print("<http://www.RinkyDinkElectronics.com/>", CENTER, 227);
myGLCD.setColor(0, 0, 255);
myGLCD.drawRect(0, 14, 319, 225);
// Draw crosshairs
myGLCD.setColor(0, 0, 255);
myGLCD.setBackColor(0, 0, 0);
myGLCD.drawLine(159, 15, 159, 224);
myGLCD.drawLine(1, 119, 318, 119);
for (int i=9; i<310; i+=10)
myGLCD.drawLine(i, 117, i, 121);
for (int i=19; i<220; i+=10)
myGLCD.drawLine(157, i, 161, i);
// Draw sin-, cos- and tan-lines
myGLCD.setColor(0,255,255);
myGLCD.print("Sin", 5, 15);
for (int i=1; i<318; i++)
{
myGLCD.drawPixel(i,119+(sin(((i*1.13)*3.14)/180)*95));
}
myGLCD.setColor(255,0,0);
myGLCD.print("Cos", 5, 27);
for (int i=1; i<318; i++)
{
myGLCD.drawPixel(i,119+(cos(((i*1.13)*3.14)/180)*95));
}
myGLCD.setColor(255,255,0);
myGLCD.print("Tan", 5, 39);
for (int i=1; i<318; i++)
{
myGLCD.drawPixel(i,119+(tan(((i*1.13)*3.14)/180)));
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
myGLCD.setColor(0, 0, 255);
myGLCD.setBackColor(0, 0, 0);
myGLCD.drawLine(159, 15, 159, 224);
myGLCD.drawLine(1, 119, 318, 119);
// Draw a moving sinewave
x=1;
for (int i=1; i<(318*20); i++)
{
x++;
if (x==319)
x=1;
if (i>319)
{
if ((x==159)||(buf[x-1]==119))
myGLCD.setColor(0,0,255);
else
myGLCD.setColor(0,0,0);
myGLCD.drawPixel(x,buf[x-1]);
}
myGLCD.setColor(0,255,255);
y=119+(sin(((i*1.1)*3.14)/180)*(90-(i / 100)));
myGLCD.drawPixel(x,y);
buf[x-1]=y;
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some filled rectangles
for (int i=1; i<6; i++)
{
switch (i)
{
case 1:
myGLCD.setColor(255,0,255);
break;
case 2:
myGLCD.setColor(255,0,0);
break;
case 3:
myGLCD.setColor(0,255,0);
break;
case 4:
myGLCD.setColor(0,0,255);
break;
case 5:
myGLCD.setColor(255,255,0);
break;
}
myGLCD.fillRect(70+(i*20), 30+(i*20), 130+(i*20), 90+(i*20));
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some filled, rounded rectangles
for (int i=1; i<6; i++)
{
switch (i)
{
case 1:
myGLCD.setColor(255,0,255);
break;
case 2:
myGLCD.setColor(255,0,0);
break;
case 3:
myGLCD.setColor(0,255,0);
break;
case 4:
myGLCD.setColor(0,0,255);
break;
case 5:
myGLCD.setColor(255,255,0);
break;
}
myGLCD.fillRoundRect(190-(i*20), 30+(i*20), 250-(i*20), 90+(i*20));
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some filled circles
for (int i=1; i<6; i++)
{
switch (i)
{
case 1:
myGLCD.setColor(255,0,255);
break;
case 2:
myGLCD.setColor(255,0,0);
break;
case 3:
myGLCD.setColor(0,255,0);
break;
case 4:
myGLCD.setColor(0,0,255);
break;
case 5:
myGLCD.setColor(255,255,0);
break;
}
myGLCD.fillCircle(100+(i*20),60+(i*20), 30);
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some lines in a pattern
myGLCD.setColor (255,0,0);
for (int i=15; i<224; i+=5)
{
myGLCD.drawLine(1, i, (i*1.44)-10, 224);
}
myGLCD.setColor (255,0,0);
for (int i=224; i>15; i-=5)
{
myGLCD.drawLine(318, i, (i*1.44)-11, 15);
}
myGLCD.setColor (0,255,255);
for (int i=224; i>15; i-=5)
{
myGLCD.drawLine(1, i, 331-(i*1.44), 15);
}
myGLCD.setColor (0,255,255);
for (int i=15; i<224; i+=5)
{
myGLCD.drawLine(318, i, 330-(i*1.44), 224);
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some random circles
for (int i=0; i<100; i++)
{
myGLCD.setColor(random(255), random(255), random(255));
x=32+random(256);
y=45+random(146);
r=random(30);
myGLCD.drawCircle(x, y, r);
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some random rectangles
for (int i=0; i<100; i++)
{
myGLCD.setColor(random(255), random(255), random(255));
x=2+random(316);
y=16+random(207);
x2=2+random(316);
y2=16+random(207);
myGLCD.drawRect(x, y, x2, y2);
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
// Draw some random rounded rectangles
for (int i=0; i<100; i++)
{
myGLCD.setColor(random(255), random(255), random(255));
x=2+random(316);
y=16+random(207);
x2=2+random(316);
y2=16+random(207);
myGLCD.drawRoundRect(x, y, x2, y2);
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
for (int i=0; i<100; i++)
{
myGLCD.setColor(random(255), random(255), random(255));
x=2+random(316);
y=16+random(209);
x2=2+random(316);
y2=16+random(209);
myGLCD.drawLine(x, y, x2, y2);
}
delay(2000);
myGLCD.setColor(0,0,0);
myGLCD.fillRect(1,15,318,224);
for (int i=0; i<10000; i++)
{
myGLCD.setColor(random(255), random(255), random(255));
myGLCD.drawPixel(2+random(316), 16+random(209));
}
delay(2000);
myGLCD.fillScr(0, 0, 255);
myGLCD.setColor(255, 0, 0);
myGLCD.fillRoundRect(80, 70, 239, 169);
myGLCD.setColor(255, 255, 255);
myGLCD.setBackColor(255, 0, 0);
myGLCD.print("That's it!", CENTER, 93);
myGLCD.print("Restarting in a", CENTER, 119);
myGLCD.print("few seconds...", CENTER, 132);
myGLCD.setColor(0, 255, 0);
myGLCD.setBackColor(0, 0, 255);
myGLCD.print("Runtime: (msecs)", CENTER, 210);
myGLCD.printNumI(millis(), CENTER, 225);
delay (10000);
}