search for a certain user's posts

[Urizen]

Hello!

In the past I could find posts that a certain member of Microsoft Discussion
Groups had posten by entering his/her username in the "Search For:" field and
then selecting a certain Group in the field "In:".

Though, recently, searching in the way described before, only brings the
results for old posts. The most recent posts doesn't appear anymore in the
serch.

How often is the search index updated? Why is it no longer updated anymore?

Is there any other way to search for a certain user's posts?

I am thankful for any help.

Best regards,
Rui Nunes