Yahoo Not Downloading Attachments

For the last few weeks I have been unable to download from my yahoo account.  I have tried different browsers (Chrome, IE) but the same thing happens.  It says that it is "scanning" but then the download doesn't actually show up.  This is new, as I have been using yahoo's services for more than a decade and not had any problems.  Likewise, I have had Norton IS for several years all on the same computer.  While I have done searches on how to fix, all I can determine is that I think its a Norton conflict between the embedded service within yahoo and my local.  However, I cannot figure out how to disable either one to further test.  Any ideas on how to fix would be welcome.