Can't parse WWW-Authenticate: Header correctly

I’m using Asterisk version 1.2.9.1.

I capture the packet in ethereal, the
WWW-Authenticate Header format is correctly parsed. According to RFC 3261, the format of the Header is correct, but Asterisk can’t get the nonce correctly.

the raw header format is as follow:

WWW-Authenticate: Digest realm=“zte”,\r\n\t nonce=“4c5f4edd30bd4c1f7a0fa315ecbbbb3f”,\r\n\tZTE-ID=c042aaa7643fd6007340d00960e3e99c^M

[code]
SIP/2.0 401 Unauthorized^M
Via: SIP/2.0/UDP x.x.x.x:5082;received=x.x.x.x;rport=5082;branch=z9hG4bK1b1c8e7c^M
To: sip:10111160008@x.x.x.x^M
From: sip:10111160008@x.x.x.x;tag=as2ad07e05^M
Call-ID: 06fbc91c22011d2a308fd3b33fd90248@127.0.0.1^M
CSeq: 104 REGISTER^M
User-Agent: ZTE-SoftSwitch^M
WWW-Authenticate: Digest realm=“zte”,^M
nonce=“4c5f4edd30bd4c1f7a0fa315ecbbbb3f”,^M
ZTE-ID=c042aaa7643fd6007340d00960e3e99c^M
Event: registration^M
^M

^@^M— (11 headers 0 lines)—
^@Responding to challenge, registration to domain/host name x.x.x.x
^@REGISTER 13 headers, 0 lines
^@^M^[[Klocalhost*CLI> ^MREGISTER attempt 4 to 10111160008@x.x.x.x
^@Reliably Transmitting (no NAT) to 211.96.x.x:5060:
REGISTER sip:211.96.x.x SIP/2.0^M
Via: SIP/2.0/UDP 202.x.x.x:5082;branch=z9hG4bK767a1104;rport^M
From: sip:10111160008@211.96.x.x;tag=as1f7b53d9^M
To: sip:10111160008@211.96.x.x^M
Call-ID: 06fbc91c22011d2a308fd3b33fd90248@127.0.0.1^M
CSeq: 105 REGISTER^M
User-Agent: BOL2000.COM CallingCard Platform^M
Max-Forwards: 70^M
Authorization: Digest username=“10111160008”, realm=“zte”, algorithm=MD5, uri=“sip:211.96.x.x”, nonce="", response=“e0e996de5dc1efffa8dcb8ce37513633”, opaque=""^M
Expires: 600^M
Contact: sip:s@202.64.x.x:5082^M
Event: registration^M
Content-Length: 0^M
^M
[/code][/code]