Does nobody test anything these days?

Does nobody test anything these days? 

Although I mostly use Linux, there are several Windows 7 boxes here at Vanya Towers. Supposedly protected by Avast antivirus.
They all run Internet Explorer 10 as well as Firefox.

This week there was an Avast program update to version 2014.9.0.2006.
It doesn't do anything different, but the familiar orange ball that spins when stuff is happening is now orange and blue. Whoopee!

Except, that while Firefox and Chrome run as normal, Internet Explorer has stopped dead.  What?

It turns out that it isn't quite dead. If you leave it for several minutes, it eventually renders the page you clicked on. 

After much head scratching and internet searching, the fix appears to be to disable any Avast add-ons in Internet Explorer. i.e.:-

Start Internet Explorer, and allow it to reach it's home page.  This may take several minutes. Don't click anything until it's loaded properly.

Then:-
Click the gearwheel at the top right.
Select 'Manage Add-ons'.
Select 'Show all Add-ons'.

The list should include either 2 or 4 entries for Avast Online Security.
Why 2 or 4?  Who knows.
Right-click the first one and select 'Disable'.
A box will come up to say the others will also be disabled.
Click Close, and shut down Internet Explorer.
Restart Internet Explorer, and it should work ok.

Of course, this means that IE no longer uses the Avast online protection, but if you don't go anywhere nasty you should be ok.
If, for some reason, you need to go to some random, unknown site, they first go there with any other browser.

Postscript.
In amongst all this messing about, Windows wanted me to install something called Microsoft Security Essentials, but this wanted me to remove Avast altogether.   I can only suppose it's MS trying to muscle in on the AV market.  Maybe I shall investigate this later.