PS1.5.4.1 - Problem allowing Out Of Stock ordering

[Toeareg]

I am struggling to get the Out Of Stock ordering working on PS 1.5.4.1

 

I thought these settings would do the trick:

 

 

But when i try to place a product in the shopping cart I get the message that I have already reached the maximum available quantity.

 

Anybody got a clue what I could do or check to trace the problem?

 

[Toeareg]

I have tracked the problem. For some reason the column 'available_for_order' wasn't updated in the database, so I set it to 1 manually (both in ps_product & ps_product_shop) and now it works as expected.