Searching for a system preference from the top search or the search on the administration start page results in an error: Software error: Cannot decode string with wide characters at /usr/lib/perl/5.18/Encode.pm line 176. The search term used was "date".
Looks ok on master with perl 5.20.1. Looks good on sandboxes too, with perl 5.10.1.
I will retest - it appeared on my master installation this morning.
Not sure what caused the problem in the first place, but I no longer see the bad behaviour in my installation. Thx for testing Jonathan!