If you're referring to Mac viruses, yes they do exist. But in my 11 year experience using a mac, I've never come across one from the net. The 2 that I found were on CD & Zip disks passed to me from fellow students. But yes, it is wise to scan anyway. Personally I only scan manually, not from every moment every file enters my computer (which is probably not wise).

LW apparently has a technique of attempting to repair files that have corrupted due to their downloading (will go thru a process of attempting to re-download those parts that are missing/seemingly corrupted at the end of downloading). However, if the file was already corrupted at its source, then not much can be done!

If you discontinue dwnlding a corrupted file when the question window is put to you, chances are that LW will close down in order that it stops downloading the file. The choice is yours. There definitely are corrupted files being offered out there whether the uploader is aware of it or not!?!?!?

Sounds like you've changed over to a mac platform from pc. Good choice! It must be a bit of a testy period whilst you become accustomed to the small differences ("let's not forget" where Windows GUI originated in the 1st place!)