Asterisk & nimbuzz registration

Is there anyone that has nimbuzz working with asterisk ?

I have a nokia 6210 with nimbuzz & it registers, I can make & receive calls but after a few minutes re-registration fails I have have to manually re-register. This means I will not get any incoming calls.

Nimbuzz tries to register after expiry:

REGISTER sip:asterisk SIP/2.0
Authorization: Digest username=“200”, realm=“asterisk”, nonce=“530f41f1”, uri=“sip:asterisk”, algorithm=MD5, response="eb6fcc80e046cd0add55c7e94169358b"
Call-ID: 7beb02ef1d4b5471a7de04a40f9d610
CSeq: 755 REGISTER
Expires: 300
User-Agent: Nimbuzz Symbian SIPv1.0

Asterisk shows SIP/2.0 401 Unauthorized:

SIP/2.0 401 Unauthorized
CSeq: 755 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
WWW-Authenticate: Digest algorithm=MD5, realm=“asterisk”, nonce=“61fda3d6”, stale=true
Content-Length: 0

So its saying the nonce is stale and they are different. Is there any way around this problem ?