Hello Guys

I had the same problem and I found a solution that work for me, I think this is a bug in the grid.treegrid.js these are the details:

1. I'm using the jquery 1.4.2 and jqGrid 3.7.2, (I checked the last download available today and have the same problem in the grid.treegrid.js file)

2. I declare my treegrid like in the demos, i'm using “adjacency” model and json data type.

3. My problem was that the nodes expands with no problems, but when I try to collapse the node just do nothing.
After a long and detailed debugging, I found that in line 238 col 54 of the grid.treegrid file : if(this[parent_id] == rc.id)