What file format are you using, at the bottom of the import window? WAV, FLAC, MP3? You’re probably going to get different metadata results in each. As far as I know, in WL7 you’ll get no metadata in WAV, some in FLAC, and some in MP3. I would try them all to see whats transferred. I believe there’s also a metadata checkbox on the import options tab.
I think Wavelab 8 added metadata in WAV from rips. But if I was in Wavelab 7 and wanted quality and metadata, I think I’d probably use FLAC.
You might want to try out a demo of Wavelab 9 to see if that would work better for you.