  The EUV excess emission from the clusters A2199 and A1795 remains an
unexplained astrophysical phenomenon. There has been many unsuccessful attempts
to `trivialize' the findings. In this Letter we present direct evidence to
prove that the most recent of such attempts, which attributes the detected
signals to a background non-uniformity effect, is likewise excluded. We address
the issue by a re-observation of A2199 which features a new filter orientation,
usage of a more sensitive part of the detector and, crucially, includes a
background pointing at $\sim$ 2$^o$ offset - the first {\it in situ}
measurement of its kind. We demonstrate quantitatively two facts: (a) the
offset pointing provides an accurate background template for the cluster
observation, while (b) data from other blank fields do not. We then performed
point-to-point subtraction of the {\it in situ} background from the cluster
field, with appropriate propagation of errors. The resulting cluster radial
profile is consistent with that obtained by our original method of subtracting
a flat asymptotic background. The emission now extends to a radius of 20
arcmin; it confirms the rising prominence of EUV excess beyond $\sim$ 5 arcmin
as previously reported.
