Update and new records problem

[oyvjel]

I am unable to both update old issues and add new ones from one textfile containing both existing issues and new ones. Looks like I have to identify the the new issues and import them from a file without existing issues.

My issues in Redmine have a user-defined field to hold a unique issuID from an external system. I want to update old issues in Redmine and add any new ones from the external dataset. Apparently this is not possible.

I match the "Select unique-valued column" with the column for the corresponding user-defined field.

If I check "Update existing issues" I get a warning for the new record (Warning: Could not update issue 1 below, no match for the value OJ015781 were found), and the new issue is not added. The existing issues are updated.
I would expect this behavior if I check "Ignore non-existant issues", but this also happens when this is unchecked. Only the warning is ignored.

If I dont check "Update existing issues" all records are imported as new issues, leading to duplicated issues in redmine for the existing "unique" external issuID.

Is this a bug, a missing feature or am I missing something?