Elvira and others,
The PNG issue gets solved this way (finally):
HB_CFLAGS += -DPNG_NO_STDIO
Anyhow, we are planning to avoid the use of this library, included in Harbour, and try to support the PNGs using standard Windows GDI+
Paco García has been so kind to provide us his GDI+ functions to manage PNGs
Thanks Paco!