Hi again!
Thank you for the example, it was very useful and I was finally able to get it to work, the only thing is that I found out two things
1) The jQgrid source doesn't work with certain versions of jquery
2) For some odd reason the last subgroup in the second to last subgroup is making the next group disappear. You can see that in your jsfiddle when you open the Blank sub group under DSK1 and then close it, it eats the next sub group thats under the number 2.
Do you have any idea how we can fix this?