DVD Architect appears to be resolved, for me.
Sony suggested a thorough clean of the Registry and fresh installs . . which I got my dealer to do . . and I can now include vids that were on the "naughty" list - which semed to be anything over a few hundred Mb . . when joined DVDAS was having none of it.`
Difficult to know for certain, but I've made the longest Vid compilations yet (all rubbish stuff) but it plays on my TV combo.
So if anyone has such issues, the easy thing to do is clean it out . . the Win Uninstall is NOT sufficient as there must be traces of weakness lurking..... and thankyou to all whose suggestions I've followed and tried as well.
What's not clear is what may have caused the glitch "Ruination" is closer , . . in the first place; as DVDAS was running OK for maybe a year - but all were short vids maybe up to 9 mins only.
=Perhaps we should all compile a very long set of clips to make sure Vegas and Architect are running OK - this will require 2x ovrernight processing, if you hasve only two-cores like my PC.
A whole 16G memory card should be enough material - and that would be an easily repeatable TEST.