swa66 - 7:59 pm on Aug 23, 2013 (gmt 0)
IMHO one needs to test every different version of IE that is agreed upon as being supported. Using a real browser installed as the default browser.
To that purpose I keep a collection of virtual machines around (and only for that purpose).
Every time MSFT makes yet another IE version I clone a virtual machine (if the #$%^ thing want to run on an older OS) and try to see if and when I can zap the oldest one.
But assuming that the different IE versions behave themselves isn;t in the books for MANY years to come.