Remember in the about SQL based logging I mentioned that there is an internal buffer that log4net has before it dumps all into the database.
While it seems to be quite useful when running in production, in development environment you would want to see immediate messages in the logs, especially when troubleshooting.
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<appender name="ADONetAppender_SqlServer" type="log4net.Appender.ADONetAppender" >  
**<****bufferSize value="1" ****/>**

If the buffer is not explicitly set, it will be defaulted to 512 :-)

Happy logging!