I've noticed that there's specific songs in my iTunes library, that constantly read out as "0.0" in my BPM's.

I thought that this was initially because they were DRM protected, but after burning them onto CD, and re-ripping them back into my computer, it appears I still have this issue.

When I load the tracks, it'll give me the proper BPM read-out, but it doesn't save the info, and still continues to register as "0.0".