I'm not sure what could be causing that. My initial thought is that you're running PHP 5.2 and I've let some PHP 5.3 code slip in, but that doesn't appear to be the case.
Are you able to access your server logs and find the entry for this error?
If not, I'll be happy to FTP/SSH into your server and take a look. If you want to send me your server details, email my username at gmail dot com.
John