Drop down of Remove Combinations does not work for a group of items

Hello,

We are removing some obselete combinations and using the 'remove combinations'..this is working for most of the items except for one group of items.

This is becaue the LOVis now shoing the dropdown for 'Remove Combinations' set to 'Yes' befroe we remove the combinations.

Please advice why the LOV does not work for a group of items--what causes this LOV not drop down.. What is preventing the drop down to display..I am assuming there is a simple SQL which controls this.

Please look at the working LOV.

Thanks for your inputs

rgds

Aqil