Magento Configurable Product Only Allowing 1 Associated Product 1.6.2

[BizLab]

I’m trying to create a configurable product collection containing multiple associated products as in this Wiki article.

 

http://www.magentocommerce.com/knowledge-base/entry/tutorial-creating-a-configurable-product

 

The problem is that the initial attempt was successful, and i was able to create a configurable product by combining 3 simple products. When i try to create another, the product selection table at the bottom of Product > Associated Products (tab) > Super product attributes configuration i am only able to select one item and the rest are disabled / un-checkable.

 

This seems like a bug, but i’m not sure. Creating a new collection has the same (fail) result.

 

• Magento Version 1.6.2
  
• MediaTemple DV 4.0 64bit
  
• CentOS 5.x
  

 

Any help is appreciated.