Database corrupt on restart

I installed the WAR distribution of 1.2-M1 on a tomcat 6 instance.

It starts up fine, but when tomcat is restarted archive can no longer access the derby database.
This may be caused by a crash (Archive seemed to stop responding and failed on restart)

Here is what looks like the important part of the stack trace:

Caused by: java.sql.SQLException: Failed to start database '/var/emineo/archiva/users', see the next exception for details.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)
... 96 more
Caused by: java.sql.SQLException: Another instance of Derby may have already booted the database /var/emineo/archiva/users.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
... 93 more
Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database /var/emineo/archiva/users.
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.privGetJBMSLockOnDB(Unknown Source)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.getJBMSLockOnDB(Unknown Source)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.boot(Unknown Source)