Check Box control hosted in a C1 Silverlight DataGrid unchecks on column sort or filter

I have a C1 Silverlight DataGrid that hosts a Check Box control that allows the user to select rows. When I sort on a column I lose the values in the Check Box controls.

Any ideas?

How are you implementing it?
Have you used our C1DataGrid_CustomColumn sample as a starting point?

You can see an online demo here - Data Visualization - DataGrid - Custom Columns.
The source code is your [installation folder]\Samples\C1DataGrid_CustomColumns.

Seems to me that you are changing the value in the checkbox but not in the underling object bound to it. Please be sure you have TwoWay Binding in the column.

If it doesn't help, can you post a simple project showing the problem?

Regards