Can you find an example of a ringed space $(X,\mathcal O_X)$ and an injecitve $\mathcal O_X$-module (i.e. an injective object in the category $\mathfrak{Mod}(X)$ of $\mathcal O_X$-modules) which is not an injective sheaf (i.e. an injective object in the category $\mathfrak{Ab}(X)$ of sheaves of abelian groups on $X$)?
This question is related to this one.