My recent investigation indicates that ItemStateListener's behaviour on TextField of Java Runtime for S60 3rd Edition FP2 has been changed.
On S60 3rd Edition FP1 devices, ItemStateListener.itemStateChanged will be called when the user has selected a phone number from his/her phonebook in order to insert it into a TextField. In contrast with that, my E75 does not call the method when I have selected a phone number from my phonebook. Although -- as far as I know -- Nokia has not announced this change, this behaviour has been also confirmed with emulators of S60 3rd Edition FP2 SDK and S60 5th Edition SDK.
I cannot understand why Nokia has changed the behaviour of phonebook interaction case only; altering directly the contents of a TextField still calls itemStateChanged method.