Do you clear the cache & delete cookies a lot? What connections are you referring to? Don't use virus blockers on my mac. What does pop up blockers have to do with my problem?
Good point about lots going on here. Maybe that's why it's only a periodic problem. Thanks.
B.
It should clear your cache and delete cookies when you log off. If you don't, it'll definitely slow you down.
I have my Mac set to clear the cache every day, and ask permissions for any cookies from sites I haven't been to.
You SHOULD use a virus blocker, because I have actually had a virus on this Mac and another I've had and it's an expensive piece of equipment to mess up.

Also, may be why you're running slow.
Pop-up blockers, depending on their settings and what ones they actually are, can block new windows you try to open, or loading new windows, etc. You can try disabling your pop-up blocker, clearing your cache, deleting your browsing history,( or anything else that takes up space) and see if any of that help.
As far as "connections" go. I meant your actually wiring, router, and modem. Make sure all lights are wiring properly, all wires are attached firmly. Troubleshoot.
*Also, if you ARE going through a router, the connections can often be reset or you may not be getting s strong enough signal. With all of the refreshing pages and new threads being posted, ads, etc the amount of everything going on could be too much for your router to handle. You can buy a new router, or get a "wifi-extender", possibly..