EC Error - (28) Operation timed out with 0 out of -1 bytes received

[elcantodelospajaros]

Hi I'm getting this Express Checkout Error:

An error occurred when we tried to contact the payment processor. 
Please try again, select an alternate payment method, or contact the store owner for assistance. ()
 - (28) Operation timed out with 0 out of -1 bytes received

Here's the ouput of IPN Check,

IPNCHECK.PHP - Version 1.0

IPN TESTING - POSTING to PayPal via: ssl://www.paypal.com:443

IPN TESTING - Confirmation/Validation response: RESPONSE RECEIVED - Communications OKAY

Script finished.

Now this is the output of the curltest.php?ssl=1

28 Operation timed out with 0 out of -1 bytes received

Array
(
    [url] => "https://www.zen-cart.com/testcurl.php"
    [http_code] => 0
    [header_size] => 0
    [request_size] => 192
    [filetime] => -1
    [ssl_verify_result] => 20
    [redirect_count] => 0
    [total_time] => 15.712871
    [namelookup_time] => 0.003362
    [connect_time] => 0.003457
    [pretransfer_time] => 0.713148
    [size_upload] => 0
    [size_download] => 0
    [speed_download] => 0
    [speed_upload] => 0
    [download_content_length] => 0
    [upload_content_length] => 0
    [starttransfer_time] => 0
    [redirect_time] => 0
)

With regards to php support, here's an excerpt:

PHP Version 4.3.9

CURL support 	enabled
CURL Information 	libcurl/7.12.1 OpenSSL/0.9.7a zlib/1.2.1.2 libidn/0.5.6

MySQL Support	enabled
Active Persistent Links 	0
Active Links 	0
Client API version 	4.1.20
MYSQL_MODULE_TYPE 	external
MYSQL_SOCKET 	/var/lib/mysql/mysql.sock
MYSQL_INCLUDE 	-I/usr/include/mysql
MYSQL_LIBS 	-L/usr/lib/mysql -lmysqlclient

Directive	Local Value	Master Value
mysql.allow_persistent	Off	Off
mysql.connect_timeout	60	60
mysql.default_host	no value	no value
mysql.default_password	no value	no value
mysql.default_port	no value	no value
mysql.default_socket	no value	no value
mysql.default_user	no value	no value
mysql.max_links	Unlimited	Unlimited
mysql.max_persistent	Unlimited	Unlimited
mysql.trace_mode	Off	Off

I had a lot of trouble installing the cart, and had to comment the lines testing CURL. Now that I'm switching from IPN to CE, the CURL problem shows up again.

My service provider claims that there's no proxy configured.

Any idea? Appreciate your help. Thanks.