Sale Order Updating Problem

Version OC: 1.5.4 (Clean Install)

Ok, I got some problems when editing sale orders in admin site.
When we received an order, and the status is pending, assuming customer contact us to add a product OR to amend/change qty of specific items in his/her order. So what i do as below,
1. Change the status of that specific order to "Canceled".
2. Go to Sale - Order - Click Edit - Go to Tab Products.
3. Now the problem is eg. Product with code T0-2011 qty in inventory is: 10. When I add this product T0-2011 with qty 11 to the order list, and the list is updated with T0-2011 quantity 11, at the same time it prompted me 2 messages:
1st is "Warning: Please check the form carefully for errors!"
2nd is "Products marked with *** are not available in the desired quantity or not in stock!"
And the weird is i supposed can't get to continue saving it, but it can! After i click button "Save" in the top right corner, it succeed to save it. And i got this message "Success: You have modified orders!".

So is it a bug? or Am i doing something wrong here?
Please help and guide. Thanks.

I think I understand what you say is the problem. I believe that the messages are just for warnings to let you know that you need to check your stock, before of after saving the order.

Because of the way the stock is checked for the admin editor there will be sometimes you might need to ignore the error and save anyway.

For example if there was 10 of product1 in stock and a customer placed any order for the full 10 leaving 0 in stock. Then the customer changes their mind and asks for the order to be changed to 5. So the admin removes the 10 of product1 from the order and adds 5 of product1. Because the edited order has not been save yet, the stock for product1 is still zero, so a warning will appear when adding the 5. Of cause you know there is enough stock because you will be putting 10 back and then taking 5 when you save the order. So you want to be able to save despite the warning.

I hope that makes sense.

Thanks for the reply.

Thanks for open my mind yeah it makes sense but i still feel that message or warning will make user confusing.
So the conclusion is every time we want to edit the order, we have to manually check our inventory first?

If you have enough inventory for the new quantity (before cancelling the old quantity) the warning shouldn't appear at all. It is an area that could do with improving.

Yeah, i totally agree with you.
But it seems must doing something with the javascript? im totally zero knowledge with the javascript.