A quick solution would be to make sure your DOD:S and Vent are on the same permissions.
I.E. When u run vent Right-click, Run as Administrator. Because sometimes if u have dod ran as admin vent cant talk.
so make sure the both are Ran as admin.
2, IF that dosent work best thing i can tell u is to restart the vent. its a pain but it is a necessity when u lag and glitch the bind button.