Firefox, flash, web page: Who's fault?

[Tom Horsley]

I've been noticing this a lot lately, and I wonder where to point the finger:

A web page will have a row of mouse-over menus. That row will be located
on the page over an area with flash content.

If I mouse over the menu, the menu gets drawn underneath the $#@! flash
content.

For example, I just checked si.com and saw this happen.

Is firefox screwing up the window stacking order? Is flash screwing up
the window stacking order? Are web page designers ignoring something
they are supposed to specify? I don't even know who to blame :-).