  In this letter we report on the detection of a new feature in the complex
structure of the horizontal branch (HB) of the Galactic globular cluster NGC
6752. In the U vs. (U-V) plane, the HB shows a discontinuity (``jump'') at U-V
~= -1.0 (corresponding T_e ~ 23,000 K). This ``second U-jump'' adds to the
u-jump identified by Grundahl et al. (1999) in a dozen of clusters at T_e ~
11,500 K. We show that this new discontinuity might be due to the combination
of post zero age HB evolution and diffusion effects. We identify 11 AGB-manque
stars. The comparison between post-HB star counts and evolutionary lifetimes,
as predicted by canonical stellar models, shows good agreement, at variance
with similar estimates for NGC 6752 available in the literature.
