Why not sync my iPhone anymore?

I have the iPhone 3G and is jailbroken. I never had a problem when you sync but now I get something popping up that says: "The iPhone can not be synchronized. An unknown error occurred (13019)). restared I have my computer and everything, but the message continues to rise. Can someone please tell me what to do?

Try this: http://iphoners.org/fix-error-itunes-anunknown-erroroccurred-13019/ Hope it helps