  Supersoft X-ray sources are commonly believed to be stably burning white
dwarfs. However, the observations of some supersoft sources show dramatic
variability of their X-ray flux on timescales ranging from days to years. Here,
we present further observational data of the supersoft X-ray source RX
J0527.8--6954 exhibiting a continuous decline over the past 5 yrs. With no
clear trend of a concordant temperature decrease this might suggest a
evolutionary scenario where the WD leaves the steady burning branch and the
combined effect of reduced luminosity and cooling at constant radius produces
the observed effect.
