Tab/Page Problems = SiteAdvisor/Yahoo?

I've been having trouble for awhile now with two things and I think that they may be related (?).

1. Often, the webpage I am viewing will suddenly switch to a Yahoo! Search page - almost, it seems, as if by static electricity or if I breathe too hard (though I'm pretty sure that-that's not the case). I do use a Yahoo email account, and also have Yahoo set as my default search engine.

2. On occasion, when I try to load a webpage, I will suddenly (again, very quick-like) get multiple tabs attempting to load, and displaying across the top in rapid-succession across the tab bar. It hadn't happened for awhile, until last night, when suddenly I had "55" (literally) tabs attempting to load before I could stop them, all with "Untitled" as the heading.

I have a feeling this all has to do with me having (using) both McAfee's SA and Yahoo's "SearchScan" (or SafeSearch - or whatever it's called), which is "Powered by McAfee".

I have enjoyed having them both, however I think there is a conflict between them, and was hoping someone could tell me if that's possible (likely), before I get rid of one of them.

Thanks,
g ...