In Beilinson's paper "On the derived category of perverse sheaves", he proves that the realization functor $D^b\mathrm{Perv}(X,R)\to D^b_c(X, R)$ is an equivalence when $R$ is a field. Here $X$ is a complex quasiprojective variety with analytic topology. This is also known to be true if $X$ is a one-point space and $R$ is commutative, Noetherian, and of finite global dimension (these conditions are necessary to define Perv).
Does anyone know of examples where this fails if $R$ is not a field?