daemon cannot generat track gap correctly?

[shadewither]

Operating System: WinXP SP2
DAEMON Tools Version: have tried 3.47&4.03

i'd like to ask a question first: how do cd drives recognize gaps between tracks? i'm unable to find any info about this.

problem:
i've a cd-xa disc(2 session) like:

FILE "LILITHGAME.bin" BINARY
TRACK 01 AUDIO
INDEX 01 00:00:00
...
TRACK 15 AUDIO
INDEX 01 31:33:06
TRACK 16 MODE1/2352
REM INDEX 00 33:45:24
INDEX 01 36:17:24

from real cd disc & mds+mdf image，Alcohol and EAC report:
track 15 = 2min; gap between track 15&16 = 2min
that is correct and what i want

with the above cue sheet, Alcohol and EAC report:
track 15 = 4min; gap = 0
The PROBLEM IS: when i tried to add INDEX 0 for track 16, nothing changes.
then i wrote another cue sheet:

FILE "CDImage.wav" WAVE
TRACK 01 AUDIO
INDEX 01 00:00:00
...
TRACK 15 AUDIO
INDEX 01 31:33:06
REM POSTGAP 00:02:32
FILE "DATA.ISO" BINARY
TRACK 16 MODE1/2048
REM PREGAP 02:32:00
INDEX 01 00:00:00

i tried POSTGAP and PREGAP, but still gap=0
(INDEX 0|POSTGAP|PREGAP all work between AUDIO TRACKs)

therefore i can conclude that it is a bug of daemon?(because EAC and Alcohol recognize real disc & mdf+mdf image correctly)

//ADD
the last(data) track is the 2nd session, but when loading cue sheet it becomes 1st session as a part of audio tracks.
there are no command for cue sheet to claim a new session
maybe daemon-tools could introduce a new feature to automatically create new session(or take new command like REM SESSION X)?