iTunes error -3150?

[RAMd®d]

When trying to import/move some movie and music files between three Macs, nothing happens for several seconds, then I get a window showing error -3150.

Google shows several hits, all related to downloading from the iT Store.

All my Macs are authorized, and I've done this several times before so I have no idea what's going on.

[rankandfile]

I've had that error when downloading from the iTunes Store. Haven't tried importing between Macs.

I reinstalled iTunes and the problem stopped.