Failed in PayPal Payment Page (Always Loading, no further progress)

Sorry for asking help. Before my posting, I spent several hours to search and resolve this porblem.

----Question Start----
It's always "Loding" in paypal payment page, more than several hours. No other information, just "Loading"

What I Did?

1. Zencart v150
2. PayPal Express Checkout
3. I'm sure my PayPal account and PP EC module are set correctly, because I received payment before (1.39h), and I have checked my setting several times.

Other Information
My Site: http://www.digitalframe8.com/store/
Logs: www.digitalframe8.com/store/pplogs.7z
Screenshot: www.digitalframe8.com/store/ppscreen.gif
----Question End----

Thanks in advance!

If I failed to provide full information, please let me know. I'll add it ASAP.

Additional Info:
I run crultester.php and ipncheck.php, it seems everything is OK. Here are infos from curltester.php and ipncheck.php.

---Start of IPNCHECK.PHP----

IPNCHECK.PHP - Version 1.3.9
CURL RESPONSE RECEIVED - Communications OKAY
IPN TESTING - Response Received via CURL -- COMMUNICATIONS OKAY
IPN TESTING - Confirmation/Validation response with fsockopen(): FSOCKOPEN() RESPONSE RECEIVED - Communications OKAY
Default method likely to be used for communications is: CURL, with the fallback method being FSOCKOPEN if possible.
Script finished.

----End of IPNCHECK.PHP----

----Start of curltester.php----

CURL Test Page
This page is intended for testing CURL behaviour. You should be accessing this page via CURLTESTER.PHP running on YOUR server.

You submitted the following fields and data:

Array
(
    [field1] => This is a test
    [statuskey] => ready
)

Data validation
Good
Other Info
Your server IP address is: 74.220.200.167.
Your system identifies itself as: Zen Cart(tm) - CURL TEST
Copyright © 2003 - 2012 Zen Ventures, LLC - Powered by Zen Cart™

Array
(
    [url] => "http://www.zen-cart.com/testcurl.php"
    [content_type] => text/html
    [http_code] => 200
    [header_size] => 179
    [request_size] => 212
    [filetime] => -1
    [ssl_verify_result] => 0
    [redirect_count] => 0
    [total_time] => 0.117911
    [namelookup_time] => 0.019217
    [connect_time] => 0.06775
    [pretransfer_time] => 0.067894
    [size_upload] => 37
    [size_download] => 2183
    [speed_download] => 18513
    [speed_upload] => 313
    [download_content_length] => 2183
    [upload_content_length] => 37
    [starttransfer_time] => 0.117724
    [redirect_time] => 0
)

----End of curltester.php----

Sorry for asking for help! I fix it.

I just clear these 3 menu.
Locations/Taxes: Zone Definitions
Locations/Taxes: Tax Classes
Locations/Taxes: Tax Rates

And swithch to PayPal IPN. It works fine, now.

I'm testing PayPal EC, there is a new problem... I'll post if I can not fix it.

Thank you all!