2013-02-23 10:14 - edited 2013-02-23 10:20
We we're able to successfully connect C7-00 and Lumia 920 using NFC, so I do not think it is limited to WP8 devices only.
You need to make sure that NFC chips on each phone are placed closely together. Positioning of NFC on each phone can be seen here:
Nokia C7 - http://nds1.nokia.com/phones/files/guides/Nokia_C7
Lumia 920 - The NFC area is on the back of your phone, near the camera.
If still the same, you can try to pair each phone to other devices which supports NFC just to isolate where the issue is.