Upgrade to 1.0.13jp resulted in garbled characters

[computerlady911]

I attempted to upgrade my customer's site to 1.0.13jp from 1.0.12jp.  The text in the back end became garbled and the text in the "who's online" and "search" modules were also garbled.  We restored the site back.

The only instructions I have found are in japanese.  My client translated them as well as she could but perhaps I am missing something.  The english version only requires that you upload the files.  We are using UTF8 and have been successfully running 1.0.12jp for several months.