Edges pointing down / Leaves rolling into a tube / ~25 days old

Hey
I have kinda strange problem with my plant. It's ~25 days old and I gave it any nutrients only twice. Edges, especially tips, are curling (pointing) down and leaves are rolling into a tube a bit. Only the level of quite young leaves has this problem, but it is not getting better, I'm afraid.
Tips are also yellowing a bit.
Do you have any idea?

The plant is Easy Ryder F2 AF, light is 2 x 23W = ~3000 lm, humidity ~40-50%, growbox is PCBox

Could you post any pics ? its hard to say really without actually seeing it, there is a small handfull of issues that would make your plant do this.

I've posted some pics in IMG but it disappeared :/ I'll repost it...

If any moderator deleted those photos, he can write here why shouldn't I post them like this. It's just the most comfortable way of posting photos for me.

I'm sorry for bumping, but do anyone know what does this rolling mean?