Chat Log Encoding inconsistent?

[SilentStorm]

Character Encoding in Logs appears to be inconsistent even within the same file.
I got one Log where in the first few Lines the Nickname appears correctly in Western Encodings (ISO-8859-1, Windows-1252) but the ones further down appear correctly only if using UTF-8 Encoding (in which case the ones displayed properly with ISO-8859-1 will become squares).

Just found one File where this happened so far, so not sure what causes this, whether there is something wrong or if it is just something wrong with that specific logfile.

[RicoH]

Hi,

please make sure the log is not that old. We fixed something with 3.0.6 and you might having a side effects.

- Fixed writing and reading chatlog history. Please backup or delete old chat
  logs to start clean or you might feel some strange delay.

Or maybe we "fixed" more than just the delay?