This error is caused by some DevExpress components used by PDQ Inventory. A ticket has been opened with DevExpress however we understand that this problem does not occur in the later version of DevExpress which will be used in the next version (2.0) of PDQ Inventory.
Gratefully we haven't seen very many of these errors.
Error : 'CellEditor' object cannot be added to 'Border'. Exception has been thrown by the target of an invocation. Error at object 'DevExpress.Wpf.Grid.CellEditor' in markup file 'DevExpress.Wpf.Grid.v9.3;component/themes/Office2007Blue/GridView.xaml'.
Error Type : System.Windows.Markup.XamlParseException
We have a fix for the the next release, version 1.1 (release 5). We've found that if you change the selected row to any row but the first then the resize will work.