Do you run any modem tuning software such as Modem Booster etc?
These progs store the numeric values of the server addresses instead of the alpha numeric values. This way loading of a page starts immediately instead of first looking up the "translation" server for
www.pprune.org and request the required ip-address, sending it back to your browser and telling your browser to connect now to this number.
The problem is simple but annoying if a hosting service changes...new address for the ip-values but the domain name remains the same.
If you do not run any of these progs, delete all temporary internet files, clear all cookies and give it another try.
Check the setting for your dial-up access (and adsl) as there may be a proxy setting activated. Proxy do the same as modem boosters....updating takes time there.