Keith,
You have my apologies, I should have looked at your signature for the details.
I first downloaded (manually) KB951748 amongst from memory 4 other updates late Thursday afternoon, but we may have a time zone issue here, I'm in Australia.
I have had a few problems over the years installing Zone Alarm updates over earlier versions, granted spread over quite a number of PC's. Clean installs fixed the problems then and I have continued that policy ever since. I appreciate that you are supposed to be able to install ZA updates over the top of previous versions, and I have no evidence that this might be part of the problem you had, I just releated what I had done on three individual PC's at the time. (it's now 5 PC's, all with Avast).
I didn't experience your problem on any of these, and I also haven't ever seen the avast error message you describe. Two points I did omit in my previous post were that when installing ZA 7.0.483.000 I did not install the toolbar, and I did not disable or turn off avast during the installation of Zone Alarm.
Sorry I couldn't be of more help. Perhaps one of the Avast team will recognise the "transparency module" and be able to shed some more light on it.