If Bitzi doesn't have information about that file, it could mean that no-one so far has commented on the file (maybe it is a not very popular file), the files is a faked one (spam, ad) or the file name as such doesn't exist.
If you check as well the file size then I'm sure you will be able to judge whether the file you searched for is really the file you want.
Besides, scan all files you've downloaded with an Antivirus program before opening.
