jQuery Grid Plugin - jqGrid

A feature that I miss a lot is the ability to group some columns under a title.

For example, let's say we have three columns labelled "Minimum temperature for this year", "average temperature for this year" and "maximum temperature for this year". It would be nice if you could state a first line of grouping labels with the text "this year's temperature" and, under that group, the three more readable labels "min", "avg", "max". Something like:

It would be specially useful with narrow columns and could help a lot organizing the information displayed.

I've tried to do this by myself with a loadComplete callback function, adding a <tr> prior to the one created by jqgrid inside the table with the column headers, but I've found various issues regarding column resizing (headers doesn't resize properly) and sorting (jqgrid duplicates my recently created tr after clicking over a header for sorting purposes).

Any ideas?

Thanks!