We have been using ADAudit Plus for nearly a year, and receive daily summary emails that detail logon activity.  I have seen sporadic issues with user names present in this report, maybe once every other month. 

The issue appears to be some kind of encoding/decoding problem, as the characters that come out are from multiple non-English character sets, and do not translate into anything intelligible.

We are based in the US and use the standard English character set exclusively, no pictograms or accent marks in naming for users/computers/servers.

I've included a sanitized image of our report from this morning as an example, the final entry under "Top Logon failures:" is emblematic of the problem.

Any further insight or recommended troubleshooting steps would be greatly appreciated.