I created a custom tool bar as a .config file as described in your help files i downloaded.
Everything in it works fine except for the spell checker. The button image doesn't appear, and the button is not clickable.
my.config file look like:
<toolbars>
<item type="g_start" />
<item type="netspell" />
<item type="image" name="Find" />
<item type="g_end" />
</toolbars>