Arduino Due RCSwitch 433 TX pin problem

Hi, I’ve bought an Arduino Due and i have serious problems with the 433TX module transmit pin, it stays on also when no transmission is needed, i’ve tested the output voltage with a multimeter on the TXpin and it keeps the pin to 3,3v, the real problem is that it makes so much interference that i can’t use 433 remotes when arduino is on…

This is the part of code:
mySwitch.enableTransmit(4);

this is the library that I’m using: https://code.google.com/p/rc-switch/

How can i solve it?
Thx