Black Ops Multiplayer no longer loads for me (odd situation)

I'm having an odd and frustrating issue. My ps3 can load up black ops (along with all my other games), but, of late, I can't access Online multiplayer. I can play Zombies, Campaign etc. (and I can play online multiplayer on Modern Warfare 2 and COD4 if that has any significance)

The main issue is that when Multiplayer is selected from the menu it doesn't load. The loading icon is seen the whole time. I've tried different Black Ops discs and they don't work while mine does on other ps3s.

This started after my game froze while playing and upon restart the problem arose.

I was thinking that it may have to do with the lens being dirty(?) but all my other games work so that's probably not the best theory.

Is this a common issue? or does anyone know or can suggest a fix?

sigh

(I posted this on the main Black Ops forums and got no response)

The only thing I can think of is try to delete the game data and NOT the save data and try again if that doesn't work than call support.

I've deleted the saved data, game data and reset the ps3 to default settings. The only thing that I haven't done is format the PS3 and I'm hoping to avoid that.

Which support should I contact?

First contact Activision support all info should be on the back of the manual if that doesn't work call Sony and see if they could do anything.

ok. here's the update with this story.

the problem is fixed. and an odd problem was solved with an odd method.

I deleted the game data then went to multiplayer (without installing the update) and strangely it worked. then I restarted, installed the update again and I was able to connect to multiplayer once again. Luckily I did this before restoring my ps3.

note that it wouldn't work if I had installed the update right after deleting it (had to access the multiplayer menu before reinstalling the patch)

and thank you to liquid snake for attempting to help out, appreciate it.