Tab Mix Plus

Using:
TMP 0.2.4 beta
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b4) Gecko/20050817 Firefox/1.0+

I have new tabs set to open to the right of the current tab. When I open a new tab, regardless of how I do it (menu, Ctrl+T, mouse gestures) it seems to add a tab (the length of the tab bar grows) and change to the tab just to the right of the current tab (like it's supposed to), but instead of a new blank tab, it's the one that was to the right to begin with.