Ah, well done, you successfully found out something I couldn't....!
Even on the HP website it doesn't ever say inkjet - it says 'toner like...' which I must admit I thought was a bit suspicious....!
This makes sense coz I'm telling you, not one jot of the stuff budges! Darn it. That's a new printer too - so not even any chance of replacing it any time soon....!!
Thanks for your reply x