How can I fix this?

[nat965]

It's sometimes caused by internet being slow as well.

[VelvetClover]

Clear your cache. Helps me most of the time.

If Safari is not the web browser you normally use try clearing your cache

(didn't see kromium's post)

How do I go about clearing my cache?

[wiktoria]

Which browser are you using?

[beth]

It's sometimes caused by internet being slow as well.

this. i used to get this all the time on my internet at home, cause it's so bad.

[karter]

If you are using Internet Explorer , right click it and go to Internet Properties , clear all history and stuff
If its Mozilla , same steps as above
If its Google Chrome , click the tool icon , go to options , In the 'Under the hood tab' click clear browsing data