I2C and tone

Hello, I am working on a project that is an airsoft bomb, it just counts the time, and the players can activate and defuse it.

When the bomb is activated, it makes a 250 millis sound (4 beep per second) untill the bomb comes to 10 seconds, then it makes a long beep until second 0 and it "explodes".

But I found a problem, the 1602 LCD is connected via I2C to the arduino, and when the bomb is activated, it misses some beeps, and when it makes the long beep it "flashes" and doesn't make the full tone, so it misses tones.

The fact is the problem is only when I2C is activated. Tried the same sketch without lcd-i2c library and it works well. How could i solve that?

Thanks ;)

Which Arduino board are you using ? Which display ? and which I2C library ?

I tried Arduino Uno, Mega and Pro mini (chinese, all bought in banggood.com), with the same result.

I2C interface: http://www.banggood.com/es/IIC-or-I2C-or-TWI-or-SP-Serial-Interface-Module-Port-For-5V-Arduino-1602LCD-p-80365.html

LCD: http://www.banggood.com/es/Wholesale-1602-Character-LCD-Display-Module-Blue-Blacklight-New-p-25345.html

The library is the one that comes with arduino IDE