refer to http://irowiki.org/wiki/Finding_The_Moving_Island_Quest
for step 10

i actually have all the stuff,but the old man still doest want to give the item.
Written is tough vines as one of requirements,and dropped by dryad
I think RRO has different name over same item it's call thin Trunk.
but this item seems to be wrong requirement items.

*p.s. SS will be given later

No, it's called Tough Vine on RRO. And it is still dropped by the Dryad.

Are you sure you aren't mistaking the Dryad for the Parasite? They look very similar, but the Parasite is in Umbala Fields, and drops the Thin Trunk. Dryad is in Umbala Dungeon, and drops Tough Vine.

Here is the difference: PARASITE versus DRYAD