does not work yet if you tag the files
What do you mean ?
My test case
Tools/Settings/Metadata: all keywords settings unchecked (since I don't want to use DB categories right now)
Edit IPTC/XMP Editor: Mode = 'XMP only', all multiple selection settings checked but the last one ('Replace only if original value is empty')
I clean XMP and IPTC metadata of my two pictures (let say P1 and P2). I check also they don't have any DB categories.
I select P1 and I do ctrl-I.
I go to keyword panel, I write "kw1" and I add it doing 'Return' and then Save. I check that kw1 has been added to P1 through the XMP panel of Info windows (dc.subject[1] kw1).
In the same way, I add kw2 to P2.
Now I want to add kw3 to both P1 and P2 in order to have {kw1, kw3} for P1 and {kw2, kw3} for P2. So I multi-select P1 and P2 and then I do ctrl-I. What I have to do to get the expected result (using Save All, of course) ?
NB. I tried with Ubuntu under Wine and with Windows XP.