Ok, maybe I've not been clear:
-You have an Ecutek ECU, newer than '02
-You want to flash it with ECUFlash (It's just like Ecutek), using the Tactrix cable.
"On all other ECUs the security aka "lock" is in the rom file itself", so we know there's a lock there, in the rom of this ECU, from Ecutek.
-You click Write to the ECU, in Ecuflash, using the Tactrix cable.
"that's it", which means that the flashing process is completed undisturbed and at the end, your replacement ROM is in place.
Basically you reflash an 03+ Ecutek ECU, with Ecuflash and the security lock from Ecutek does not stop this.
Good to know, seems like others are not able to do this..