  The accreting millisecond X-ray pulsar SAX J1808.4--3658 shows peculiar low
luminosity states known as "reflares" after the end of the main outburst.
During this phase the X-ray luminosity of the source varies by up to three
orders of magnitude in less than 1-2 days. The lowest X-ray luminosity observed
reaches a value of ~1e32 erg/s, only a factor of a few brighter than its
typical quiescent level. We investigate the 2008 and 2005 reflaring state of
SAX J1808.4-3658 to determine whether there is any evidence for a change in the
accretion flow with respect to the main outburst. We perform a multiwavelength
photometric and spectral study of the 2005 and 2008 reflares with data
collected during an observational campaign covering the near-infrared, optical,
ultra-violet and X-ray band. We find that the NIR/optical/UV emission, expected
to some from the outer accretion disk shows variations in luminosity which are
1--2 orders of magnitude shallower than in X-rays. The X-ray spectral state
observed during the reflares does not change substantially with X-ray
luminosity indicating a rather stable configuration of the accretion flow. We
investigate the most likely configuration of the innermost regions of the
accretion flow and we infer an accretion disk truncated at or near the
co-rotation radius. We interpret these findings as due to either a strong
outflow (due to a propeller effect) or a trapped disk (with limited/no outflow)
in the inner regions of the accretion flow.
