Hello and thank you for contacting Infragistics. Binding fixed records is considered to be a new product idea since we do not have a built-in collection for managing fixed records. However what you can do is create a derived XamDataGrid that contains a new fixed records collection that can link between your data with eg. a IsFixed property to tell which records should or should not be fixed. I attached a basic sample of how to do this with Selection and also added a fixed records collection but only fixed the first row to show this example easily. 

MultiSelectListBindingProblem.zip

You can suggest new product ideas for future versions (or vote for existing ones) at <www.infragistics.com/.../ideas>.
Submitting your idea will allow you to communicate directly with our product management team, track the progress of your idea at any time, see how many votes it got, read comments from other developers in the community, and see if someone from the product team has additional questions for you.
Remember when submitting your idea to explain the context in which a feature would be used and why it is needed as well as anything that would prevent you from accomplishing this today. You can even add screenshots to build a stronger case. Remember that for your suggestion to be successful, you need other members of the community to vote for it.

Let me know if you have any questions.