Problems importing keywords with image

I have exported keywords from another program (IMatch) to both embedded iptc and xmp files. The problem is that I can't get LR to assign the keywords to the pictures when importing, or when trying the ''import meta from xmp file'' option. I have tried with both jpeg- and cr2-files (cr2 is raw from EOS 20D). The strange thing is that all keywords assigned to the pictures shows up to the left in the keywords panel, so LR somehow reads the keywords from the files and knows about the existence of these keywords, but, as I said, does not assign the keywords to the keywords field of the respective images. The keywords show up perfectly fine in Adobe Bridge.