Wierd problem. Project content panel shows no files

I’m having this weird problem with Nero Premium 7.0. I start a new project and add files to it, but the left panel (the one that show the files you add) shows no files. The project size bar shows the used space correctly and my DVDs burns OK, and the folder tree works just fine, but still the file list won’t appear. So far the problem has appeared creating data and video DVDs, I haven’t tried other project/media types.

Searching Google has leaded me nowhere. Has anyone experienced the same problem? Any ideas on how to fix this? Many thanks in advance for any feedback on this issue.