An instruction when pushing potentially non DWORD-aligned strings to the stack can potentially cause the SP to become a value non-divisible by 4. Aside from the serious performance hit from a misaligned stack, NT Kernel calls rightfully fail to execute in non-apparent ways.

ie running "MoveFileA" after misaligning the stack fails with GetErrorCode ERROR_NOACCESS = 998 (0x3E6)

Which deceptively is unrelated to file permissions/access