Which version of LimeWire are you using?
I'd suggest they are auto detected by LW as being spam search results & gives them that trash icon. Depending on LW version, this can be set or reset in preferences. If you believe a search result is good but has the trash icon beside it, select that result, click the trash icon at bottom right of search results & this will change it's icon to normal.

And I can assure you, LW does make mistakes in deciding search results are junk or not. Selecting which is & which is not junk helps to train the filter .. it's a 'learning' filter.