Aha! THANK YOU William, that indeed sounds probably why some are "different". I must say I'd wondered a bit.
But all the more reason then to go straight to the Yahoo Profile, that EVERYONE (with a Yahoo Id) has, regardless of what "directory" they may choose to be in.
Now HatedJ has FOUND my lost thread, I assume this change WAS made earlier, but has since been lost with the newest update of vBulletin, so I daresay Jeff will/night resuscitate it soon.
(HatedJ - I googled for phrase "yahoo profile", which I see doesn't actually occur in that thread 
, then I also checked ALL my threads in the "Suggestions" forum - forgetting that the "Suggestion" had been resolved and thus moved to "Squashed bugs"!
What would we/I do without you ? 
)