Have CIS version 3.13 for two days now have tried to update AV several times, Have XP service pack 3, no other AV or real time protection on machine. Just Windows Defender and I see no issue there. Also the only firewall is CIS. Have no troubles updating anything else or browsing the internet. Running IE 8. Error 106 no connection. Have made no initial changes to program from first installation. Can not start machine in safe mode to do updates from web site directly. AV updater doesn’t even attempt to connect. Right away goes to error 106. Have tried 50 times to do manually. And it hasn’t done it automatically. Using Cricket broadband wireless modem. None of the topics address this situation for me. What good is it if I can not get the initial update. :-\
Did you try this:
Seems I had some left overs from Norton IS. Once I ran the clean up tool from them, I started getting updates…All is working well. Thank you for your reponse. 
Left overs from previously installed program can be a pain. In case there is no clean up you can try the following to manually remove them.
We are gonna take a look to see if there are some old drivers of your previously uninstalled security programs are still around. Go to Device Manager → View → show hidden devices → now look under Non Plug and Play drivers → when you see a driver that belongs to your previous security programs click right → uninstall —> reboot your computer.
When the problem persists make sure there are no auto starts from your previous security programs. Download Autoruns and run it.
This program finds about all auto starts in Windows. This tool can therefore seriously damage Windows when not handled properly. After starting go to Options and choose to hide Windows and Microsoft entries, to include empty locations and then push F5 to refresh.
Now check all entries to see if there are references to your previous security program. When you find them untick them. After unticking reboot your computer and see what happens.