We are having problems with our Playstation 3. On our Black Ops online we only get to a certain point on the game & it only stays there. We be wanting to play with other people online. We looked to see if maybe the enthernet cable was not plugged in right or something, but it says that it's conneted. We don't know what to do?

The last months is PSN hacked for several times so the problem is not on your PS3 but PSN itself.
Check if you haven't lost any money on your acount. The hackers have stolen more than 70 million id's and can have access to your acount. So keep an eye on your PSN acount.

Agreed, you should have had an email from PSN by now saying how their network has been hacked, hence the down time to try and stop them stealing yours ond other information, this however was not the case and they apparently have taken all your details and information including credit card info that you put into psn, so as xan mentions before it would be wise to check your bank account or if your parents have used their credit cards their account to check no unusual payments have been made.