Rockbox doesn't display some of my songs

[Cabbalistic]

Make that a lot of my songs. I'm new to Rockbox, just installed it yesterday so bear with me.  
I noticed while browsing the database under 'artists' several names were missing. Then, under one particular artist, most of the songs weren't listed. Now, all these files do show up when I boot with the original firmware.
What could be the problem? How do I fix this?
And oh, none of these songs were purchased from Apple.

[Febs]

Use a good tag editor like mp3tag to ensure that those files are properly tagged.