Be wary of using the Resume/Find sources function. If you use it, don't use on many files at one time. Perhaps 1-3 at a time.

You could try one of the nightly builds of LimeWire cvs builds (4.13.4jum490) which are not official releases & are betas. But sometimes one version may solve a particular person's problems. Other than that, perhaps stepping back a version to when this was not a problem. Which version did this problem start with? It sounds like 4.14.8. Which version did you use before this was happening?

I'm not sure if it will make any difference but try disabling the options under Performance which is in the Advanced section of preferences. (The reason I make the suggestion is they've been having some bug issues with Mojito. Also Ultrapeer can add a certain amount of traffic that can give "some" osx users problems with slowing & freezing ... happened to me.)