Very small random effect estimation in lmer but not in stata xtmixed

I am using the lmer function (in the lme4 library) to analyse some
data where individuals are clustered into sets (using the SetID
variable) with a single fixed effect (cc - 0 or 1). The lmer model
and output is shown below.

Whilst the fixed effects are consistent with stata (using xtmixed,
see below), the std dev of the random effect for SetID is very very
small (3.5803e-05)compared to stata's (see below 1.002). Any ideas
why this should be happening please....?

I am happy to share my data if that helps.