gtf-launch error while building library

Quartus 5 Nios II 5

Windows XP Pro SP2

Mapped local Directory as Drive T: eg: C:/Project/test

when I build eCos on a mapped drive (t:) I always get

make[1]: Leaving directory `/cygdrive/t/Software/eCos/examples/example_build/hal/nios2/arch/current'

/cygdrive/t/Software/eCos/examples/example_install/gtf-launch: not found

make[1]: *** [/cygdrive/t/Software/eCos/examples/example_install/include/cyg/hal/system.h-t] Error 127

make: *** [build] Error 2

make: Leaving directory `/cygdrive/t/Software/eCos/examples/example_build'

when I build it from C:/Project/test It works:-

Why ?

I have tryed changing permissions on the mapped drive, didn't help