Yes i came across that site today while looking on the internet for clues. Could not find any references to the implications of having changed user accounts though. Just wondered if i have mucked things up. I think i will go with Pondini's directions for resetting the time machine and throwing away prefs (beforehand). But was hoping that someone passing by here would know specifically about the user account issue or anything else relevant.
SO still grateful for any comments on my conundrum.