Funny, it works for me when I just DCC myself. I used this script to double check it was being sent right:
on ^*:CHAT:*: {
echo -s $1- | haltdef
}
and it echo'd only to my status screen and NOT the chat I had open. Sound like you have a script conflict there. How many ON CHAT events do you have in that same file? More than one? IF you do (and I wont know till you tell me) that could be the problem right there. Duplicate event types in the same file have historically caused problems with strange occurances.