Hi and welcome to the forums, MRRJJ42.
I think I might have found something to help you out there. A user, dustinbrutal... had a similar issue.
Disclaimer: from community.us.playstation.com
How he fixed it:
After browsing around (and no help from live chat..) I fixed it.
Apparently my modem's firewall was set too high for the PS3. I reset it to low and signed in no problem.
If anyone else is having the problem I suggest trying to see what your firewall security is set to!
Not sure if this is exactly what you're going through, but give it a shot and we can go from there.
Also found some more info about the error itself: Link to it
What kind of connection do you have? Is it a wired one or is it a wireless one?
Also, some more info for you to try...
Please try the following: 1. Reset your router. Then go to the Home screen and select [Settings] > [Network] > [Wi-Fi Settings] to connect to the access point again. For details on how to reset your router, refer to the router's instruction manual. 2. Update the router's firmware to the latest version. For details, refer to the router's instruction manual. 3. Contact your Internet Service Provider (ISP) to check the status of your Internet connection. 4. If you cannot connect to PlayStation®Network, check the status of PlayStation®Network at the Sony Computer Entertainment website for your region.
Some info from said article.
There are some other similar situations listed under the category, 'Related Answers', if this one doesn't work. Let us know if it works ok.