It was drawn attention to on Page 34 of the Mozillazine site that there was a small bug in Fast Dial 1.90.

If the Toolbar button is Mouse centre clicked Fast Dial 1.90 will not open in a New Tab in FF 3.

This was confirmed by Telega

This problem only seems to effect Version FD 1.90 when used in FF 3.

With Fast Dial Ver 1.90, In Firefox 2.x, Mouse centre click on the Fast Dial Toolbar Button opens Fast Dial in a new Tab just fine.