working with scheduled task with drive image XML

hi there
am having a problem getting my schedule task to auto run with full compression. based on version 1.31 which is still free for commercial use, its available parameters for full compression is /c as opposed to /c1 or /c2

here's my setup
...\dixml.exe /bc /td:\bkupsys\drive_c /s- /c

the schedule works fine with no split image (/s-) but i can't seem to get full compression to work i.e. compress = good (slow) it always takes the default
if anyone can help, i'd be grateful, cheers.