TITLE: Failure of Theorem of the Cube?
QUESTION [10 upvotes]: I am trying to understand the theory of cubical structures and am interested in knowing if a disconnected commutative group variety whose identity component is a semi-abelian variety satisfies the theorem of the cube.
Recall that if $X$ is an abelian variety and $L$ is a line bundle on $X$ that is rigidified along the identity sectionn, then the 
Theorem of the Cube implies that the line bundle
$$
\Theta(L) := m_{123}^{*}(L) \otimes m_{12}^{*}(L^{-1}) \otimes m_{13}^{*}(L^{-1}) m_{23}^{*}(L^{-1}) \otimes m_{1}^{*}(L) \otimes m_{2}^{*}(L) \otimes m_{3}^{*}(L)
$$
admits a unique trivialization that makes
$$
\Lambda(L) := m^{*}(L) \otimes p_1^{*}(L^{-1}) \otimes p_{2}^{*}(L^{-1})
$$
into a symmetric biextension of $X \times X$ by $\mathbb{G}_{m}$.
Here $m$ denotes the multiplication map, $p_i$ the projection maps, and 
$m_{\underline{i}}$ the morphism $X \times X \times X \to X$ given by summing the
coordinates whose indices are in $\underline{i}$.
More generally, Breen proved this fact remains true when $X$ is a semi-abelian variety.
Does this statement remain true if we allow $X$ to have non-trivial component group?
If not, what is a example of a rigidified line bundle that does not have canonical cubical structure.
Does the theorem remain valid you rigidify along $1$ fixed point on every component (rather along the identity element)?
Added  As BCnrd notes, over a more general base the formulas should be modified by adding the term $0^{*}(L^{\otimes \pm 1})$, which should be thought of as $m_{\emptyset}^{*}(L^{\otimes \pm 1})$.  This (rigidified) line bundle is trivial when the base if a field, but not in general.

REPLY [7 votes]: Uniqueness may fail if $X$ is a finite group: any two cube structures "differ" by a "quadratic" map $X\to \mathbb{G}_m$. If, say, $X=\mathbb{Z}/n\mathbb{Z}$ and $\zeta$ is an $n$-th root of unity, then $m\mapsto \zeta^{m^2}$ is such a map. 
This of course implies non-uniqueness whenever the component group of $X$ admits nontrivial quadratic maps to $\mathbb{G}_m$.