After posting this problem to other section I decided to report it here hoping it there is a bug somewhere that you guys can fix!

Here we go:
I created a few custom fields categories with their values representing the sizes of some t-shirts and added some products..
Then I tried to add some more options directly to the database following the pattern "value 1; value 2; value 3" etc..
My problem is that when I go to the VM admin panel all the products I added their sizes directly to the database have only selected the "value 1".
So if a t-shirt should have 3 sizes.. I get 3 times "value 1".. but if I select the sizes inside the VM menu then it saves them correctly.
(The reason I need to add the sizes directly to the database because I want to add products massively instead one by one..)
I run:
Joomla 2.5.11
VM 2.0.24