problem in Netscape

[Ketan Mehta <ketan.mehta@xxxxxxxxx>]

hi all,
	this is not technical problem. But is causing problme.
	I am using Netscape Communicator 4.72, and also composer as my e-mail
client.
	problem : i have my address book , now if i select any address from it
by double clicking then whole netscape closes down - communicator(all
windows) and composer. It causes data lose many time and i am unable to
use addressbook. it is causing problem..
	so anyone knows solution or have faced such a thing. pls help me out.
also do i need to upgrade to any version or to apply patch.
	
	thanks in advance
bye
Ketan