Can I use ajax with fbTooltip? I attempted to use it but the resulting window ignores all CSS classes. When I have used ajax with regular floatbox windows, all CSS classes were included.

Basically what I'm attempting to do is have the look and feel of a regular floatbox type window displayed on hover and then close it on mouse out.

I believe I have found the problem. Checking with firebug showed the data as a regular iframe. I had type:ajax within a containing div within data-fb-options but it should have been within data-fb-tooltip. Onward and upward.

To confirm what you found, options placed on a containing div are inherited by standard floatbox links in that div, and not by fbTooltip or fbContext elements. Tooltips use data-fb-tooltip for their options, context boxes use data-fb-context, and standard floatboxes use data-fb-options. It is only data-fb-options that can be broadcast by inheritance throughout a div. The tooltip and context boxes need a separate options mechanism because a link can host both a tooltip or context and a standard floatbox at the same time.

And to complete the thought...
Tooltips and context boxes can't do the containing div inheritance trick the same as standard floatbox links because any and all element types can be hosts for tooltips and contexts. If they were inheritable, every element of all types at at any depth within the div would have to pick them up.