I just upgraded from 184.108.40.206 to 220.127.116.11 After rebooting I noticed that Smart Security becomes non-responsive when attaching a new external usb 2.0 drive. Not just Smart Security, it somehow brings down the whole system, I had to use "reset" button to restart. Tried rebooting multiple times. Later I found out that even some external usb 2.0 drives that were connected and detected during booting still caused Smart Security to hang. Only when all the external drives were disconnected (except eSATA ones) and then after rebooting I was able to go back to SS 18.104.22.168 using system restore. Now I am back to 22.214.171.124 and everything is working fine again. Perhaps I have to add, that recently I had (3-4 times?) a small problem with version 4 too - always after rebooting, but it goes away after rebooting again: Once I got "GUI cannot communicate with the kernel" And a couple of times the internet was completely blocked (but LAN working) and SS (but only SS) not responding. Should I have been more patient with SS 5 and waited for some initial scan to complete or something? Still, it should never be not responding, and when it affects the stability of the whole system - even worse. --------- My computer is 4 years old GA-X38-DQ6 with quad-core Q6600 @ 2.4 GHz, XP SP3 32 bit with 4 GB of memory. I was not using /3GB switch. May be relevant: I have 3 network adapters in my PC active simultaneously with three different ISPs.