The problem is probably in Opera's mishandling the sdict dictionary download pages. I noticed this on OS2006 and OS007HE. Try MicroB. I personally use a small script with wget command ($1 is .dct file name):
wget --post-data="agree=ON&entcode=SWXHQY&seccode=PVFGWkdkVlNH WjFW&file=$1" -O $1 http://sdict.com/rsc/downdict.php