SQL*XL: away with MySQL has gone away
 
Some MySQL databases as setup such that the connection is dropped after a very short period of time. Sometimes this is even set at short as 10 seconds. My guess administrators do this for security reasons.  
 
To be able to use these databases in Excel these 'unstable' MySQL connections have been stabilised in SQL*XL. You should experience no more MySQL connection drops. Hopefully this removes the dreaded message: MySQL has gone away.