>No, I don't want to disable the use of checkboxes, I need them. The thing is that there are certain nodes that I don't want to be checkeables.

I had a similar (but reverse I think) problem and David Frankenbach (sp?) came up with a workaround in Re: Treeview - programmatically UNcheck a mouse-checked node Thread #731098 Message #731673.

It may work for you (maybe a little change needed).

good luck