if you put for example an orange in your quickbar and eat it the icon greys out but still resides in the quickbar

Can confirm this.

Still, for the time being..
this seems to be a bug, but you can easily circumvent the behaviour just by placing any other item on the quickbar slot that has this ghosting item still left and the slot will become active (or "in use") again.

Can confirm also. The item's model 'husk' is left in the quick-bar, basically a 3D un-textured white model is left. It can be dragged outside of the bar for it to be dropped though, so it isn't game breaking.

Windows 8.1 64bit
DayZ first Alpha release

Doesn't seem like a bug to me. You can just drag the icon out of the quickbar and it goes away. If I switching my inventory around a bit and perhaps drop an item on the floor that was in my quickbar, I don't really want it to disappear out of my quickbar so that I have to put it back there when I pick it up again. Just remove things from your quickbar that you don't want anymore by dragging them out of it.

I have that bug always with a baseball bat, if I have a baseball bat at slot 1 and I directly swap the bat with a hatch from the floor via inventory, I will have a hatch in my inventory but a bat at slot 1 - and I cant use this one.

I don't think its a bug.
Actually I consider it a feature. It's highly usefull while picking stuff up when your bags are full and you have to place something you've got in your quickbar on the ground for a sec.

The fact that the icon becomes greyed out makes it obvious this is a design choice, not a bug.

It's not a bug, if you watch the item is white in the hotbar. This means that you don't have the item in your inventory.
You can drag an item in the hotbar away for clear that slot.

It is a feature. It is clonky, though.

I think maybe there are some things that should not even get to go there. Like food? I don't like having to remove the soda and orange and banana either. I do like that other things stay there. For example, earlier today my friend needed a pistol, so I gave him mine. My inventory listing went grey. About 5 minutes later, I replaced my pistol with a new one. And it was still available off the bar. I was happy to not have to reset that.

I will say that I have played about 30 hours already. In my first 10 hours, this was a much larger problem than it has been in the last 20. Recently, I have had no difficulty.

Yea, It's a feature. Example:
You have a canteen water in your pants and in your hotbar. You find new, better, pants. So you switch pants and you take the canteen from the old to the new one.
The canteen is still in the hotbar, and you don't have to reset that.
Understood?

I consider this a feature and I would like it to stay, it's very useful.

Yea it's useful

This issue is fixed in experimental 0.45.12499.
If you now drop an item which is in your hotbar the icon will disappear correctly.

BUT if you put an item from your hotbar in your hands and throw it away, then there will be still a "bugged" grey icon.

Well, I have my second long rifle in my hotbar ... coloured if i have it in my hand and grey, when I forgot to pick it up again. I think it's really handy.

If you open your inventory and then click and drag the hot bar icon anywhere other than your inventory and let go, the hot bar icon will disappear.

Hi everyone,
thank you for your feedback!
This is something that has been improved and the current state is considered acceptable for now.
Regards,
Andy