IMHO I'm not sure why you'd bother replacing the old ones in that case. Since they will still continue from where the new ones are at. Since the downld.dat file is the record keeping file. If the old downld.dat file was completely corrupted in the 1st instance, then perhaps just doing Sleepless's 1st part of his suggestion (points 1-4.)

* Ah ... I just realised your problem ... until the files recontinue they will show zero %. But after they start downlding they will continue from where they were! So search for the files again on the network & use the 'Get more results' function & perhaps you'll get lucky & they'll restart downlding. If no luck after a persistant effort, then do Sleepless's suggestion ... at least points 1-4. But simply using the Find Sources / Resume button is NOT a greatly effective technique of finding sources. Search is the best way! You do know about the Get more results search function right? Right-click the search result tab & check the options.