I have just setup a cisco 7970g and a linksys spa-942 with asterisk 1.4beta3.
Cisco 7970g issue - all the extensions register and show up on screen as expected but when any of the extensions are dialed from another phone regardless which one it is they all ring to the first extension on the 7970g display, so I don’t really know what extension the call is really coming in on even though I can pick up the incoming calls (on the ringing first extension).
Linksys spa-942 issues - I setup two extensions; 1001 and 1002, they both show as registered on the web interface but on the phone screen itself all four extension buttons to the right only show 1001, and when calls are dialed from any of these butons the receiving end shows 1001 and never 1002. When 1001 is dialed from a different phone it works fine but when extension 1002 is dialed from another phone it says unavailable when this phone is supposed to also be registered as 1002. I have just upgraded the firmware to the current 5.1.4 .