OSX Snow Leopard Freezing from yahoo cookies

Hi there.

I am using as MacBook Pro 2009 laptop at my university. For a while it has been freezing while playing movies, browsing, listening to music...basically any time. The thing is these freezes don't seem to be consistent as sometimes I can watch a whole movie without it ever freezing and then other times it might freeze two times in a minute. It normally freezes for about 15 seconds then everything is normal again. It can be very annoying especially when am trying to do research etc.

I replaced my hardrive about 4 months ago, so am pretty sure it is not that. However looking on another post they suggested looking at my console and the same error keeps coming up:

2011/10/22 12:08:24 AM com.yahoo.YahooContactSyncAgent[1626] 00:08:24.038 [Yahoo! Sync:1626] ERROR (.yahoo.cookies.get_ytcookies): curl_easy_perform() failed: code = 7, message = Couldn't connect to server

2011/10/22 12:08:24 AM com.yahoo.YahooContactSyncAgent[1626] 00:08:24.038 [Yahoo! Sync:1626] ERROR (.yahoo.sync_client.create_session_from_token): error getting cookies: code = 211, message = libcurl returned error. see log for more messages

2011/10/22 12:08:24 AM com.yahoo.YahooContactSyncAgent[1626] 00:08:24.038 [Yahoo! Sync:1626] ERROR (.yahooconduit.syncclient): got an error 211

2011/10/22 12:08:24 AM com.yahoo.YahooContactSyncAgent[1626] 00:08:24.131 [Yahoo! Sync:1626] ERROR (.yahooconduit.yahooservices): Error Domain=yahoo sync Code=2 UserInfo=0x1002bd590 "This computer is not connected to the Internet"

I am reasonably sure this may be causing these freezes as my laptop is plugged into ethernet and the university requires you to input proxy information when going online.

I would really appreciate any help that you could give me.

Thanks.