I recommend to :-
1) Allow java and javaw in your firewall and virus software. Disable (or un-install) the html/web download scanner in your virus software.
2) Reduce the Max.Con. setting (bottom right corner of jD window) to 1. Reset the affected links.
3) Disable the Automatic Reconnect feature.
If this doesn't work please provide example links and
a complete and detailed log.