Bochs Bug??

[PlayOS]

I am using Bochs 1.3 and everytime I attempt to use this code

; Disable NMI
in al, 0x70
or al, 0x80
out 0x70, al

; Enable NMI
in ax, 0x70
and ax, 0x7f
out 0x70, ax

I get an invalid CMOS read\write error.

If i don't disable NMI will this affect the IDT setup or will it still be OK?

[Pype.Clicker]

the only code that disabled NMI for pmode setting i ever see was one that never worked and all the setup code that i saw working had no NMI stuff ...