Doesn't work for me either.
As soon as I activate YASU, Securom tells me on loading that a required security module could not be loaded.

What I did:
Reboot
Run Daemon 4.06 HE with SPDT 1.35
Mount H5 image (mds/mdf)
Cancel autorun
Run YASU (1.02b)
Attempt to start using H5_Game.exe

Return Error.
Tried same thing but running H5_Game.exe with the asr loader instead and get the same message.

Also, if I run YASU again (which supposedly should unhide your SCSI), I still get the error message.
If I reboot and do not run YASU but only the game file (without starting daemon either) it will tell me no cd inserted instead.

Does YASU only work under certain conditions or am I doing something wrong?