Bug: RAHasher.exe Dreamcast CHD inconsistent hashing

[torsius]

Exhibiting example CHD created from GDI (proper hash) using normal method with chdman v0.274.

RAHasher Output (bad hash value)

  C:\tools\RAHasher>RAHasher.exe
  RAHasher 1.8.0
  ====================
  Usage: RAHasher [-v] [-s systempath] systemid filepath

  -v             (optional) enables verbose messages for debugging
  -s systempath  (optional) specifies where supplementary files are stored (typically a path to RetroArch/system)
  systemid       specifies the system id associated to the game (which hash algorithm to use)
  filepath       specifies the path to the game file (file may include wildcards, path may not)

  C:\tools\RAHasher>RAHasher.exe -v 40 "c:\games\dc\102 Dalmatians - Puppies to the Rescue (US).chd"
  Found Dreamcast CD: 102 DALMATIANS (T36803N   V1.001)
  Found 1ST_READ.BIN at sector 548644
  Hashing boot executable contents (728640 bytes @ sector 548644)
  Generated hash b7bffaba501950a6ac491777b3f1981c
  b7bffaba501950a6ac491777b3f1981c

RetroArch Log (proper hash value)

[INFO] RetroArch 1.20.0 (Git 6412f4feef)
[INFO] === Build =======================================
[INFO] CPU Model Name: 12th Gen Intel(R) Core(TM) i5-12500T
[INFO] Capabilities: MMX MMXEXT SSE SSE2 SSE3 SSSE3 SSE4 SSE42 AES AVX AVX2 
[INFO] Version: 1.20.0
[INFO] Git: 6412f4feef
[INFO] Built: Jan  4 2025
[INFO] [RCHEEVOS]: Load started, hardcore active
[INFO] [RCHEEVOS]: Identifying game: C:\games\dc\102 Dalmatians - Puppies to the Rescue (US).chd
[INFO] [RCHEEVOS]: Found 9 potential consoles for chd file extension
[INFO] [RCHEEVOS]: Trying console 12
[INFO] [RCHEEVOS]: Could not locate primary executable
[INFO] [RCHEEVOS]: Trying console 21
[INFO] [RCHEEVOS]: Could not locate primary executable
[INFO] [RCHEEVOS]: Trying console 40
[INFO] [RCHEEVOS]: Found Dreamcast CD: 102 DALMATIANS (T36803N   V1.001)
[INFO] [RCHEEVOS]: Found 1ST_READ.BIN at sector 548644
[INFO] [RCHEEVOS]: Hashing boot executable contents (728640 bytes @ sector 548644)
[INFO] [RCHEEVOS]: Generated hash eed6d6c6dc3ec82337b622b06fc78211
[INFO] [RCHEEVOS]: Identified game: 17750 (eed6d6c6dc3ec82337b622b06fc78211)