MrBow wrote:
I'm already 3 days grinding nemea's lions for a quest item (harp) [euro quest lvl 18/19] ... and it just doesn't drop for me

any tips on that quest?

It's a crappy quest. I'm still working on it.
The only thing I can tell you is to keep at it. And if you get frustrated, just go and find something else to fight, or work on some other quest.
Good luck.