Sorry, to ask but I looked high and low for the answer. (Firefox 12 win 7)
The funny thing is,..I removed it on my computer (at the bottom of each bookmark folder) a long time
ago but I didn't bookmark the fix and I can't remember how I did it.

I was trying to fix it on
my daughters computer.
I looked in TMP and imported my settings on the other computer but that didn't work. So, it must have
been a firefox css mod or about config fix.
When I right click on the bookmark folder..It gives me the option of "Open All in tabs" which I use.
I hope this is a easy fix that I'm overlooking.
I appreciate any help and sorry about beating this dead horse again.