On a pivoted table, the group tree column doesn't remember resizes

Bug Report

Steps to Reproduce:

1. Go to the perspective homepage
2. Change the perspective viewer plugin to the datagrid
3. Resize the group tree column (first column)
4. Click on any of the other column headers to sort

Expected Result:

The column resize to be maintained after the sort

Actual Result:

The column resize is lost after the sort