Whenever a mashup is deployed the tables within that mashup will have record locking switched OFF with immediate affect. The side affects of not having record locking on are that multiple people can update the same record and also that pre-transition actions are run twice.

To workaround this: Whenever a deploy is the done you must go into mashup administrator and switch record locking back on for the table and restart the web server (e.g. iisreset).

This is fixed in Serena Business Mashups 2008 R2.04.