OC4J database connection timeouts

[Rick DeBay]

Connections in the pool randomly die overnight. Stack traces show that for some reason, the evermind driver is being used even though the MySql connection pool is specified.
Also, the evermind connection pool is saying connections aren't being closed, and the stack trace shows they're being allocated by entity beans that are definitely not left hanging around.
Has anyone seen this problem?

<data-sources>
<data-source
class="com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource"
name="SQLServerDSCore"
location="jdbc/SQLServerDSCore"
xa-location="jdbc/xa/SQLServerXACore"
ejb-location="jdbc/SQLServerDSCore"
connection-driver="com.mysql.jdbc.Driver"
min-connections="5"
username="xxx"
password="xxx"
staleness-timeout="3600"
alive-poll-query="SELECT 1 FROM medispan"
url="jdbc:mysql://1.2.3.4:3306/dbo?autoReconnect=true&autoReconnectForPools=true&cachePrepStmts=true&is-connection-validation-required=true"
inactivity-timeout="30"
>
<property name="autoReconnect" value="true"/>
<property name="autoReconnectForPools" value="true"/>
<property name="is-connection-validation-required" value="true"/>
<property name="cachePrepStmts" value="true"/>
</data-source>