Can't upgrade from 7609 to 77xx

We have upgradet from 7604 to 7609 --> works fine
then upgrade to 7703 (fail)
We have testet with 7701 and 7703 (the same error)
Database: MySQL
Server: Windows 2003 SP2 32bit

Errorlog:

CTIVITYID="[33]UVH@1634627" REPEATTASK="Never" RECURRING_MSG="Task repeatation" ISENDING="false" REC_END_DATE="0" REC_END_AFTER="0" REPEATEVERYDAY="0" />
<RecurringDetails ACTIVITYID="[34]UVH@20327592" REPEATTASK="Never" RECURRING_MSG="Task repeatation" ISENDING="false" REC_END_DATE="0" REC_END_AFTER="0" REPEATEVERYDAY="0" />
</Rows>
</WritableDataObject>

17.05.2011 18:00:40 [com.adventnet.servicedesk.updatemgr.util.SCPostProcessor] [INFO] : Exception while migrate task com.adventnet.persistence.DataAccessException: [ActivityReminderTask] Exception occured while inserting rows
    at com.adventnet.persistence.DataAccess.createDataAccessException(DataAccess.java:2575)
    at com.adventnet.persistence.DataAccess.insertRows(DataAccess.java:2219)
    at com.adventnet.persistence.DataAccess.add(DataAccess.java:294)
    at com.adventnet.persistence.DataAccess.add(DataAccess.java:250)
    at com.adventnet.servicedesk.updatemgr.util.SCPostProcessor.handleTaskMigWithActivityTask(SCPostProcessor.java:2222)
    at com.adventnet.servicedesk.updatemgr.util.SCPostProcessor.install(SCPostProcessor.java:174)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.adventnet.tools.update.installer.Unzipper.contextPostInstallation(Unzipper.java:1405)
    at com.adventnet.tools.update.installer.Unzipper.invokePostInstallationClasses(Unzipper.java:1237)
    at com.adventnet.tools.update.installer.ApplyPatch.installPatch(ApplyPatch.java:289)
    at com.adventnet.tools.update.installer.ApplyPatch.run(ApplyPatch.java:223)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: null, message from server: "Cannot add or update a child row: a foreign key constraint fails"
    at com.adventnet.db.api.RelationalAPI.handleException(RelationalAPI.java:690)
    at com.adventnet.db.api.RelationalAPI.executeBatch(RelationalAPI.java:665)
    at com.adventnet.persistence.DataAccess.insertRows(DataAccess.java:2185)
    ... 13 more
Caused by: java.sql.BatchUpdateException: null, message from server: "Cannot add or update a child row: a foreign key constraint fails"
    at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1401)
    at org.enhydra.jdbc.core.CorePreparedStatement.executeBatch(CorePreparedStatement.java:410)
    at com.adventnet.db.api.RelationalAPI.executeBatch(RelationalAPI.java:661)
    ... 14 more

17.05.2011 18:00:40 [com.adventnet.servicedesk.updatemgr.util.SCPostProcessor] [INFO] : Problem during installation of patch com.adventnet.persistence.DataAccessException: [ActivityReminderTask] Exception occured while inserting rows
    at com.adventnet.persistence.DataAccess.createDataAccessException(DataAccess.java:2575)
    at com.adventnet.persistence.DataAccess.insertRows(DataAccess.java:2219)
    at com.adventnet.persistence.DataAccess.add(DataAccess.java:294)
    at com.adventnet.persistence.DataAccess.add(DataAccess.java:250)
    at com.adventnet.servicedesk.updatemgr.util.SCPostProcessor.handleTaskMigWithActivityTask(SCPostProcessor.java:2222)
    at com.adventnet.servicedesk.updatemgr.util.SCPostProcessor.install(SCPostProcessor.java:174)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.adventnet.tools.update.installer.Unzipper.contextPostInstallation(Unzipper.java:1405)
    at com.adventnet.tools.update.installer.Unzipper.invokePostInstallationClasses(Unzipper.java:1237)
    at com.adventnet.tools.update.installer.ApplyPatch.installPatch(ApplyPatch.java:289)
    at com.adventnet.tools.update.installer.ApplyPatch.run(ApplyPatch.java:223)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: null, message from server: "Cannot add or update a child row: a foreign key constraint fails"
    at com.adventnet.db.api.RelationalAPI.handleException(RelationalAPI.java:690)
    at com.adventnet.db.api.RelationalAPI.executeBatch(RelationalAPI.java:665)
    at com.adventnet.persistence.DataAccess.insertRows(DataAccess.java:2185)
    ... 13 more
Caused by: java.sql.BatchUpdateException: null, message from server: "Cannot add or update a child row: a foreign key constraint fails"
    at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1401)
    at org.enhydra.jdbc.core.CorePreparedStatement.executeBatch(CorePreparedStatement.java:410)
    at com.adventnet.db.api.RelationalAPI.executeBatch(RelationalAPI.java:661)
    ... 14 more

17.05.2011 18:00:40 [com.adventnet.j2ee.deployment.service.internal.JarExtractor] [INFO] : Extraction for C:\ManageEngine\SupportCenter\mysql.zip to C:\ManageEngine\SupportCenter\mysql
17.05.2011 18:00:40 [com.adventnet.servicedesk.updatemgr.util.SCPostProcessor] [SCHWERWIEGEND] : Inside SCPostProcessor.
17.05.2011 18:00:42 [com.adventnet.tools.update.installer.RevertPatch] [INFO] : server\default\lib\report_framework.jar
17.05.2011 18:00:43 [com.adventnet.tools.update.installer.RevertPatch] [INFO] : conf\update_conf.xml
17.05.2011 18:00:43 [com.adventnet.tools.update.installer.RevertPatch] [INFO] : server\default\conf\buildInfo.xml