Hi, killer bee!
Seeing as how you want to use an add-on, the best solution would be found by asking the developer of the add-on. On his site, he says:
There have been reports of difficulties running Fast Dial Version 2.23b2 in Firefox Version 4.0
A new Version of Fast Dial Version 2.23b3 was uploaded today which hopefully addresses this problem.
(emphasis added by me)
There really is no way, currently, in FF to set a default to what page opens in a new tab (other than right-clicking a bookmark and selecting "open in new tab" or selecting the bookmark and clicking the middle button, aka the scroll button). A bit more information: browser. tabs. loadOnNewTab
Integer Determines what will be displayed in a new tab -1
: Browser startup page 0
(default): Blank page 1
: Homepage 2
: Last visited page Note: Does not work in Firefox
(see bug 269664
and bugzilla entry
(linked to above).
Perhaps there is another add-on which accomplishes this. I don't know; I use only two add-ons and rarely try out others.
BTW, you should be getting a blank page upon opening a new tab. Perhaps you have an add-on incompatible with another?