Might need a 'sticky' on this point, Nigel. Top of the page, all caps!
You can probably remember several threads I have been involved in in the past where many members don't believe ANY copyright attaches to anything that THEY feel should be free!
Yep, uploading Premium Styles from Yamaha, or styles from Midi Spot...also SMF from these companies and others...all are copyrighted...all can create problems.
Best to send these things via private email.
That's how other forums do it.
Ian