OK, thanks Adobe Press for giving me the simple solution.
(paraphrasing the tutorial) "Don't bother to assign URL's in FireWorks. You'll
do that in Dreamweaver."
When the nav bar buttons are exported from FW, they lose their URL links (but,
oddly, the pop-up menus don't!). So, after placing the FW html into
Dreamweaver, highlight each button and assign the URL link in the DW Properties
panel.
It works!
So, why does FW have the URL link box in the Properties panel?
Maybe it works for other types of elements?
Whatever.
Sorry for the ranting earlier, but I didn't see this solution in the FW
printed manual, menu, or anywhere else.
Thanks Adobe Press!
g