Well that was weird...
I decided to wait a while after reading about glitches and even horror stories with XP Pro SP 3 32 bit systems, and the threads about dodgy issues with the software updater, but after opening the interface to see what the latest program update alert was, the program update started to download of its own accord! Thinking, oh, what the hell, if it freaks I will do a clean system reinstall and think of alternatives like AVG (dear god forbid!) I let it complete, rebooted, hit the finalise update popup screen, and was a bit surprised to see Version 8.0.1483 when it had said it was updating to the last version of 7. After looking at the meh Windows 8 wannabee interface and agreeing that it seems a bit weird to have a failed desktop OS UI clone as my new startup Avast UI, I clicked on a few options, including switching off the software Updater auto update option, and then using it manually to update quicktime, VLC and a few non essential programs (I keep java, adobe, windows et al updated) I rebooted and waited for all hell to break loose.
Well, a few days now and all is quiet on the free Avast front, definition updates aok, software updates 100% green, no impact on any pc functions that I can detect, so I guess I am one of the lucky ones? Still am a bit annoyed that the thing downloaded itself against all my Avast program settings instructions, but seeing as I let it roll, I guess I can live with the UI if the protection is as good as ever. Oh, and no weekly updating and scanning clashes with my free malwarebytes either as far as I can tell.
A bit bemused by the whole episode but no disasters here...