Have the same problem updating on two computers, one XP the other 7 64bit. Had to constantly select manual update to get it to update once today. Cloud is still connected though.
Get the following when try to update manually.
Last encountered error: HTTP error (404), while trying 173.193.138.142:80//iavs5x/jrog2-653.vpx
Using Ip tool, got the following.
Host Name: a323mp.avast.com
IP Address: 173.193.138.142
Country: United States united states
Country code: US (USA)
Region: Texas
City: Dallas
Postal code: 75244
Calling code: +1
Longitude: -96.8353
Latitude: 32.9299
www.downforeveryoneorjustme.com/ says the IP is down.