adding subtitles

[raiders12]

im trying to add perm. subtitles...

i have vdub and vobsub installed, and-

open file in vdub
video/filters: selected the vobsub filter
now, when i get to the next window where i have to open the subtitles, i open it, but nothing happens. it doesnt allow me to click 'OK'

any help would be appreciated