Cookies and McAfee

I don't use McAfee. I was at a friend's house and wanted to look at my
pics on www.flickr.com. When I logged on I elected not to allow cookies
when McAfee asked (it not being my machine). I got a message saying I
had logged in but Yahoo couldn't find cookies. After that neither I nor
my friend could get into flickr without the message. Getting out
completely and trying again didn't bring up the McAfee dialog. I want
McAfee to forget about not allowing cookies on yahoo (flickr) and ask
again but we couldn't figure out how to do that. Does anyone who uses
McAfee know how to fix.
Thanks