AVG 8.5 auto install?

[#1]

Last Sunday, the AVG system tray icon reported a problem, which appeared to be the usual out of date database error. So I did a manual update, which was successful, then checked emails before shutting down. I have noticed this morning that the desktop icon is now showing as AVG 8.5 instead of 8.0.
I don't remember the update description mentioning any software update, and it wasn't a particularly long update. Previous upgrades to new software versions required the previous version to be uninstalled.
From numerous posts it is clear that there are many AVG users on the forum, has anyone else seen anything like this before?

[#2]

Yes, mine updated itself to 8.5 a couple of weeks ago as part of a standard "virus signatures" update.
Seems to be working ok though.
Bob

[#3]

Just checked and mine's updated to 8.5.339

[#4]

Thanks for the responses.
This was the most trouble-free AVG software upgrade I have ever experienced in 6 years of using it.
My only real worry is that it took me 5 days to spot that it had happened