On my pc There are two system,QNX and winxp,I want to know which bootloader you use,the default bootloader of qnx is too simple and the delay time is too short.
My comment: The NT-bootloader fail when QNX is install on an other disk.
My way to boot QNX, Windows , (Linux, FreeBSD and Solaris) is LILO with ships with most Linux-system.
,but now I have no Linux on my pc.
Then try to compile GRUB for QNX.