if the server is very busy , at times you will get this notice, or if they are running slower than normal due to maintenance. you can also try and clear all your history and cookies ,, anything that would be slowing your connection speed, One good tool to use for this is CCleaner by piriform, I use it a couple times a day , click this link and download it,, its free, they ask for donations, and have a version you can buy, but look for the download choices,, and click on the one from Piriform,, not the one from filehippo,, and Poof,, freebie,, once installed, Just run it,, you'd be surprised at all the junk it gets rid of that slows your machine to a crawl.. heres the link
http://www.piriform.com/CCLEANER