Oh! Just include one "normal" page reference to force that help compiler to process map section:

----- test.hhp -----
[OPTIONS]
Compatibility=1.1 or later
Compiled file=Test.chm
Default Window=Principal
Default topic=test.htm
Display compile progress=No
Error log file=test.log
Language=0x416 Português (Brasil)
Title=Test

[WINDOWS]
Principal="Test",,,"test.htm",,,,,,0x2000,,0x3006,,,,,,,,0


[FILES]
test.htm

[ALIAS]
HH_dummy=test.htm
HH_test=test.htm#Campo1

[MAP]
#include test.h

[INFOTYPES]

----- test.h -----
#DEFINE HH_test 1500
#DEFINE HH_dummy 1