IOUnserialize finds bad UTF8?

[René J.V. Bertin]

Hello,

I've been getting tons of

kontact[62499]: FIXME: IOUnserialize has detected a string that is not valid UTF-8, "*_³"

messages in my system.log, a burst about every 30s . Setting a breakpoint on IOCFUnserialize it would seem that this happens when Qt's WLAN scanning feature is invoked, i.e. something to do with the WiFi I have available here. 

Googling the error shows that it's a common thing, but one that is apparently without solution.

Does anyone on here have an idea?

Thanks,
René