I'd say that's your problem. This have side-FX. It can affect LW's connection quality, use up all of LW's resources & your computers & can steal all of your bandwidth. It puts a lot of stress on all of the above. It's also not so healthy for the G network with so many requests all at the one time.
Depending on how many incomplete & shared files you have, LW needs time to load them all which uses up a lot of its resources, & then tries to connect to each incomplete file one by one. By Resuming a great many files at once you're trying to do all this at once when LW isn't ready for it.
Resume can be effective. Though best if applied to just some files per session & particularly when the search results are already there or has been downlding earlier on in that session.
My advice is to turn LW on, walk away & come back 30 or mins later, & then search for the files you have priority to downld. Searching for the topic to find sources is much more effective than using the Resume or Find Sources function which has side-fx.
Exactly how long you should wait depends on how many incomplete & shared files you have. Even after loading the files which might take 10 mins for me, LW takes another 15-20 mins to try to connect to the others. The longer LW is on the more stable it is. So, I might turn LW on, forget about it & have a look at it 40 mins or an hour later to see if it's downlding or not. Some days I do need to slave over it.
See my points 2 & 3
HERE (click on link) & optimising LW's use is point 3.