Assigning the return value of new by reference is deprecated (no replies)

I had piwik installed and running just fine.. was installed like 2 months ago.. can't remember the version but it was the latest back then.

Anyway, trying to log into piwik now results in this php error:

Deprecated: Assigning the return value of new by reference is deprecated in /usr/share/php5/Log.php on line 168

What should I do? If I install a new version, will the data I currently have, stay or get erased?

Thanks!