This line works for me:

ctcp *:dcc send*:*:{ 
[color:green]  ; I use $ctime and not $time.[/color]
[color:green]  ; Using $ctime has many advantages in what may come later on.[/color]
  mkdir $+(",$getdir,$nick,$ctime,") 
  dcc get $+(",$getdir,$nick,$ctime,")

possible reasons:
1. mIRC didn't like spaces in your target path
2. : is not a valid character in a directoryname, so make sure you don't have them in your $time output

DALnet #Helpdesk
I hear and I forget. I see and I remember. I do and I understand. -Confucius