I have also a problem on windows gui.
Can not run
"-bios 1" or "-bios T1" = NASBUG1.T1 (original version)
"-bios 2" or "-bios T2" = NASBUG1.T2 (1978)
Even I select in Properties - Miscellanous - Bios - NasBug T1 or Nasbug T2
If i start the emulation it show me always Nasbug T4 (NASBUG 4).
The only way to start the right Bios is to run on command line.
As example: mess.exe nascom1 -bios T2