It's a very strange behaviour.
If even with Firefox you have the same problems, i guess the guilty should not be the browser...
You should have to search for problems in your operating system (have you updated/changed it recently?), or in a third party software (above all security software, ad blocker or antivirus/antispyware/firewall). Try to disable them and retry.
Another suggestion, verify that your pc is free from viruses or malwares.
Last thing, your provider could have implemented some sort of filters for internet trafic (but this is a remote hypothesis, in Italy they apply filters only for p2p protocols)
Edited by marcodd on 11/10/07 01:03 PM.