Well, at least it’s a gotcha if you’re me. Which as a solipist, that’s all that really matters.
Anywho, if you’re using the Infragistics DataGrid with hierarchical data that has both read-write and read-only fields, make sure your BindingMode on the read-write is TwoWay and your BindingMode on the read-only is OneWay. The documentation is. . .um. . .sparse and doesn’t describe this in much detail (or any detail really) but after struggling with it for a couple of hours this morning, Jef came by and said “Try setting it to OneWay” and what do you know, it works.