Cisco 7941 Wont go to voice mail

I have a cisco 7941 phone which has been converted to SIP
It syncs up fine with my asterisk server but no matter what settings i change on the phone or server 2 problems appear

  1. It will not connect to the asterisk server if “qualify” is set to on
  2. It never goes to voicemail, even though that extension is set to timeout to voicemail it just keeps on ringing

I think that the main problem is because “qualify” needs to be off when I think it should be on because my lg lip-6830 phone works fine with it on and the voicemail does work after so many rings

Any ideas on how to fix this?