Strange Data Grid Problem

Hi
  I have a strange problem, that may be a Microsoft thing? I have 6 data Grids. 5 of the grids have 3 rows high, med, low. The botttom grid has a dropdown cell that you can choose high, med, low for the upper grids, 1 for each grid.

OK, say I change from med to high on the lower grid, the upper grid will change highlight from med to high. Works great.

Here is the problem, the lower grid can be reloaded with different versions or the same version for that matter, from the DB. When I load a new version in the lower grid,  the functionality to have the upper grids changing to match the lower grid no longer works. I call the same code I use when it works on the initial load. Any idea's  

Thanks