safari browser

A few days ago my Safari browser stopped being able to log on to the Internet. First time this has happened in 20 years. Firefox works fine. Error message when trying to log on says... "Safari can't open the page." The error is: "The operation couldn't be completed. Operation not permitted." Did a complete re-load of the appropriate Safari version (5.1.10) for my OS ( Snow Leopard version 10.6.8). Still same error message. Has anyone else ever experienced this? Seems like the answer might be in the preferences area, could not find the answer there. Thanks.

Do you have another browser? If neither work, it could be a problem with your service provider.

EDIT: Sorry, I missed your short sentence: "Firefox works just fine." Apparently, my eyes don't.

Yes, I also have Firefox, and it is working just fine.

Is it Java? Apple blocks old versions of Java from running because of security issues. You may need to update Java.