I have constructed my dialogs such that when you rerun the package and choose Modify, a custom dialog gathers the info again from the user (same dialog used during the initial install). The CA in the Execute sequence does insert the new records in the database during the Execute sequence, I verified the existence of the records immediately prior to the WriteRegistryValues action, but the new registry entries are not created.
Obviously there is a difference between Install and Modify that I don't understand. Any help would be appreciated.