Custom Items turn into flint

[ningyou6]

I just got RPGEssentials working on my server, but the problem now is that even though I can see most items (except crossbows and bolts), when I try to use them they just turn into flint.
I have googled this problem and couldn't find anything but people saying it was flint from the start,
not TURNING into flint.

Have I done something wrong or am I missing something?

I'm running RPGEssentials 1.3.5-5 Dev.

Thanks in advance