Bitzi web lookup is the best way to see if the particular file has been reported on their database or not. You don't need to downld a file to check it. Right-click the file from the search results, then choose Advanced->Bitzi Web lookup.

Sample image at bottom of page here: How to use Bitzi Web Lookup ...

Of course you can also preview the file whilst it's downlding if bitzi doesn't list it. That'll let you know one way or the other.

This has been an age long problem. I like these comments by Sir Leeware: Quality of Content on the Network (click on link)