This usually means that your server hasn't got enough memory allocated to it to run C5 properly. You can check how much memory you have by going to 'Dashboard->System and Settings->Environment'. After the window fills with stuff, scroll down to the bottom and look for 'memory_limit='. This number is how much memory your host has allocated to your website.

You are probably on a shared hosting plan so you may have to ask your host to increase this amount. Ask them to double it and see what they say.

It says I only have 16mb, I will ask my hosting company if they can increase. Was uninstalling and installing everything with no luck. Thank you for this answer!!

I'm on a shared host and mine is set at 356M which is very high. I'm sure C5 doesn't need that much but it's comforting to know it's there.

They just increased to 64mb, and looks like things are running much faster/smoother! Thanks again for the answer - hopefully no more hiccups :-P

What host are you with? That's a really fast tech response!

Fatcow.com, been using them for a number of years. Chat support 24/7 I believe.