can't connect facebook with any browser

Please help. The only site I can't get on is facebook, I have checked parental controls, Firewall is off...I have tried chrome, safari, firefox and tried via wifi in 3 different US cities. We were preivously in China using a VPN...but now in US and can't connect to facebook. All other sites are loading ok.

When I ping, I get this:

PING www.facebook.com (69.63.189.16): 56 data bytes

36 bytes from 10.2.189.1: Communication prohibited by filter

Vr HL TOS Len ID Flg off TTL Pro cks Src Dst

4 5 00 5400 cebd 0 0000 3f 01 e35c 10.2.189.61 69.63.189.16

My airport ID is e4:ce:8f:37:d1:8e

My DNS servers are this: 208 67 222 222 and 208 67 222 200

I'm using OSX 10.6.8 and have updated software and tried all other advice I could find on this forum.

Last month, I was in China, using a VPN and facebook suddenly quit there too (although could still access other sites)...now in US, no facebook.

Can someone please help?

thanks.