Description:
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Hello

As backup-procedure we use 4 concurrent mysql-dump processes. When these processes are running, MySQLi-Prepared-Statements can't be executed and the following error appears:

Errno: 1615
Message: Prepared statement needs to be re-prepared

In my opinion it doesn't seem to be a mysql-problem because prepared-statements with PDO and "normal" mysql_query() or mysqli->query() work as expected. The error doesn't occur if no mysqldumps are running. 

Reproduce code:
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http://tmp.raphis.ch/mysqli_problem.phps

Expected result:
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All queries should return the same texts.

Actual result:
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mysqli-select, mysql_select and PDO work as expected. mysqli-prepared statements exits with:

Errno: 1615
Message: Prepared statement needs to be re-prepared