As of today, I've been having some weird behavior in searches that include the user number.
If I click on a tag in my user page, so that it performs a search for that particular tag and my user number, I'm getting no hits; for example, searching for
[group-theory] user:742 is returning no matches, even though I've posted over 50 answers in such questions.
Update: I can confirm Rahu Narain's observation that if perform the search on a tag in which I've asked a question, then the question is displayed.
Searching for just the tag seems to produce no problems. Searching only for
user:742 does find some hits, but the page result looks weird. I've tried a few users (not just me), they are all giving me trouble. The problem also seems to be occurring in Meta, with searches for user-and-tag returning no matches even when some should exist.
Update 2: I've reported this at the main site; I'm told there will be a temporary fix for the user-page links as well as one for the display problem when searching for a user in the next build.
Final Update: The searches seem to be working now. Could a moderator mark this as resolved?