Mailchimp subscriber list not automatically updated

Hi,

I now have an S2Member and Mailchimp integration issue.

I have integrated my Mailchimp account with S2Member, with correct API’s / list ID’s, however, when I test signing up through the free trial pro-form on my site:

1) Mailchimp subscriber list isn’t automatically being updated, and

2) The welcome email I have set up through Mailchimp isn’t being generated fro the subscriber – obviously relating to point number 1)

Am I missing something in these logs?

LOG ENTRY: Thu Dec 17th, 2015 @ precisely 2:53 pm UTC
PHP v5.6.15 :: WordPress v4.4 :: s2Member v151210 :: s2Member Pro v151210
Memory 4.09 MB :: Real Memory 4.50 MB :: Peak Memory 4.41 MB :: Real Peak Memory 4.75 MB
http://www.moneypigz.com/matched-betting/free/
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.80 Safari/537.36
Array
(
[args] => stdClass Object
(
[role] => subscriber
[level] => 0
[ccaps] =>
[login] => SaamAli1
[pass] => !mY$*qrrSwzY
[email] => sheffieldwpmeetup@gmail.com
[fname] => Saam
[lname] => Ali
[ip] => 83.61.218.199
[opt_out] =>
[opt_in] => 1
[double_opt_in] => 1
[user] => WP_User Object
(
[data] => stdClass Object
(
[ID] => 246
[user_login] => SaamAli1
[user_pass] => $P$B6d7MsPhR/9E9DbE/X4FlNvae1UWel1
[user_nicename] => saamali1
[user_email] => sheffieldwpmeetup@gmail.com
[user_url] =>
[user_registered] => 2015-12-17 14:53:26
[user_activation_key] =>
[user_status] => 0
[display_name] => Saam Ali
)

[ID] => 246
[caps] => Array
(
[subscriber] => 1
)

[cap_key] => wp_wxtx_capabilities
[roles] => Array
(
[0] => subscriber
)

[allcaps] => Array
(
[read] => 1
[level_0] => 1
[access_s2member_level0] => 1
[subscriber] => 1
)

[filter] =>
)

[user_id] => 246
[name] => Saam Ali
)

[function] => subscribe
[list] => 4890ea3661
[list_id] => 4890ea3661
[api_method] => listSubscribe
[api_properties] => Mailchimp Object
(
[apikey] => c23c6a20d0a4e2bd7c090af8e40090cd-us11
[ch] => Resource id #265
[root] => https://us11.api.mailchimp.com/2.0/
[debug] =>
[folders] => Mailchimp_Folders Object
(
[master] => Mailchimp Object
*RECURSION*
)

[templates] => Mailchimp_Templates Object
(
[master] => Mailchimp Object
*RECURSION*
)

[users] => Mailchimp_Users Object
(
[master] => Mailchimp Object
*RECURSION*
)

[helper] => Mailchimp_Helper Object
(
[master] => Mailchimp Object
*RECURSION*
)

[mobile] => Mailchimp_Mobile Object
(
[master] => Mailchimp Object
*RECURSION*
)

[conversations] => Mailchimp_Conversations Object
(
[master] => Mailchimp Object
*RECURSION*
)

[ecomm] => Mailchimp_Ecomm Object
(
[master] => Mailchimp Object
*RECURSION*
)

[neapolitan] => Mailchimp_Neapolitan Object
(
[master] => Mailchimp Object
*RECURSION*
)

[lists] => Mailchimp_Lists Object
(
[master] => Mailchimp Object
*RECURSION*
)

[campaigns] => Mailchimp_Campaigns Object
(
[master] => Mailchimp Object
*RECURSION*
)

[vip] => Mailchimp_Vip Object
(
[master] => Mailchimp Object
*RECURSION*
)

[reports] => Mailchimp_Reports Object
(
[master] => Mailchimp Object
*RECURSION*
)

[gallery] => Mailchimp_Gallery Object
(
[master] => Mailchimp Object
*RECURSION*
)

[goal] => Mailchimp_Goal Object
(
[master] => Mailchimp Object
*RECURSION*
)

)

[merge_array] => Array
(
[MERGE1] => Saam
[MERGE2] => Ali
[OPTIN_IP] => 83.61.218.199
[OPTIN_TIME] => 2015-12-17 14:53:26
)

[api_merge_array] => Array
(
[MERGE1] => Saam
[MERGE2] => Ali
[OPTIN_IP] => 83.61.218.199
[OPTIN_TIME] => 2015-12-17 14:53:26
)

[api_email_type] => html
[api_double_optin] => 1
[api_update_existing] => 1
[api_replace_interests] => 1
[api_send_welcome] =>
[api_response] => Array
(
[email] => sheffieldwpmeetup@gmail.com
[euid] => be4cf6fe5d
[leid] => 66629821
)

[api_success] => 1
)

https://wordpress.org/plugins/s2member/