Are you sure your not mistaking the number of "sources" for the number of "files". That number 1000 would represent the of sources available not the number of different files.
Say you did a search for "Cheeze" and got 100 in the search results, but it's only showing 3 files.
Example:
Cheeze 100
50 Swiss Cheeze
30 Cheddar Cheeze
20 Longhorn Cheeze
You see? 100 sources but only 3 files.
Another possibility is that LW has marked the missing files as junk and it is set to not show the junk files. You can change that setting in LW by going to Tools>Options>Filters>Junk, and checking the option you want, then click apply.
Also you should be aware of the large amount of fake files being circulated on the network. This thread has all the info you need to get the best search results from LW:
How to find music 
Oh, I see your on a mac. The settings may be slightly different but they should be similar.