Live protection freezing my machine

I mentioned in another thread how to fix this: start up with the shift key held down, then go into preferences and disable live protection, then reboot.

Live Protection issues are generally tied to network connection issues -- the software is failing to communicate with the cloud service that contains the live data.  For those technically inclined, it's attempting to perform a DNS lookup and read the response.  If your router for some reason can't handle large DNS datagrams (ie: it's not compliant with the DNS RFCs because someone took some shortcuts in hardware or software), this will fail.  It can also fail if the Live Protection service is saturated on your local lookup node, or if you have general network connection issues.

... adding my two cents...

My system does not freeze, but enabling Live Protection slows it down so much that working is virtually impossible.

I´ve excluded several directories and file-types and that did not help at all.

Been looking into my network connection and there is absolutely nothing wrong with that...

It´s a shame really, because for years Sophos has been my favorite AV...

-- Mountain Lion / 2.4GHz Core 2Duo / 3GB SDRAM --

Cheers

Live Protection depends upon routing of large (but still compliant) DNS packets -- so there is room for incompatability between it and lightweight routers.  In such situations, it's probably best to either disable it, or upgrade your router (depending on how lightweight it is, you may be experiencing other issues as well, that also manifest themselves as dropped traffic, non-working software, badly displayed web pages, etc.).