Asterisk > Cisco 7960G registration roubles

Hello,

Im finally getting to grips with Asterisk, Ive got it up and working with a Digium TDM11B (1xfxs 1xfxo), 1 Cisco 7960G & X-lite Softphone.

Here is the problem, my 7960 seems to un-register itself, except it doesnt. The phone is shown in ‘show sip peers’.

Example: *97 is voicemail, Extn 200 = Cisco, Extn 201 = Softphone.

If I dial *97 from voicemail after a period of inactivity I get the busy signal. If I replace the handset and immediately pick up and dial *97 again it puts me through. Same is I dial extn 201, busy signal first time, rings through the second.

Calls from the Softphone appear to be working fine, they as far as Ican tell work first time.

Any ideas how to find out what is going on?

Many thanks,

Bill