DataGrdView - ComboBox cleared on sort

[pateras]

I generate code to automatically create combo boxes to handle
relationships between tables:

http://pastebin.com/m59d8f5b0

The problem is, when I sort on any other column, the combo boxes all
get cleared. I've also noted that in doing so, I can no longer sort on
the column. I have a feeling that that might be related. Can anyone
tell me why the combo box
may be getting cleared and why I cannot sort based on the combo box
column? It has a value like the other columns.

I am happy to provide any more information as needed and would
appreciate any suggestions on how to resolve both issues.

[pateras]

"I've also noted that in doing so, I can no longer sort on
the column."

What I mean by this is that I cannot sort the column that has the
ComboBox lookup. I worded that improperly. I couldn't find a way to
edit my original post.