As far as accessibility goes, here's what I see wrong.
First of all, the tree view of options doesn't seem to read what's checked and unchecked anymore. It used to be the case that checking or unchecking an option caused it to be read the next time it was selected, but no longer. I don't know what sort of control is being used inside the tree view, but it doesn't seem to be a standard Windows control.
Second, the buttons for various options are read as buttons, and also don't indicate whether something is checked or not. Again, I don't know what sort of buttons these are, but they're definitely not standard check boxes.
These are the only glaring accessibility issues I've seen. The easiest way to fix them that I can think of would be to use standard controls.
