MEGA 2560 FREEZE with button on D39 (ALE)


I have Mega2560 with push button, one pin is connected to PIN 70 (DIGITAL PIN 39, ALE) of Mega2560, other one is to GND.

Sketch contains one line in setup:

pinMode(39, INPUT_PULLUP);

When i press fast several times on button (with different delays between press), sometimes AVR freeze.

XMCRA &= 0x7F did not help.

Please advise.

Please post your code (see point #7 in this post so that you know how to post it properly).
Please also post a schematic showing anything else that you have connected to the Mega.