Sitecore Logging for 6.5 and Up: Blank Log Entries

Always reference the assembly, Sitecore.Logging.dll, instead of log4net.dll but still call "using log4net" in your code since this entire namespace in within Sitecore.Logging.dll.

The "using" is referring to a namespace and not an assembly name.

If you don't do this, custom log files and appenders will always have blank entries written.