Ajeh:
If you want nothing for the two Tare Rates, you should use: 0:0 rather than just leave them blank.
When you say:
Do you mean you have a Zone set on the USPS shipping module?
If so, in the Zone Definitions what are the DETAILS on this Zone that you set?
In the Modules ... Shipping ... if you EDIT the USPS shipping module, down near the bottom of the settings is one for Debug set this to Log then try to checkout ... if you then look in the directory /logs (or /cache depending on your Zen Cart Version) do you see shipping logs? If so, if you read them, do you see any obvious errors?
If you are unsure how to read the shipping logs, you should Zip the log(s) with WinZip and attach it to your post ...
***USPS Version Date
2014-01-26
Enable USPS Shipping
True
Enter the USPS Web Tools User ID
Which server to use
production
Quote Sort Order
Price-LowToHigh
Handling Fee - US
0.80
Handling Fee - International
0
Handling Per Order or Per Box
Order
Decimal Settings
3
Tax Class
--none--
Tax Basis
Shipping
Shipping Zone
United States
Sort Order
1
All Packages are Machinable?
True
USPS Options
Display weight, Display transit time
USPS Domestic Transit Time Calculation Mode
CUSTOM
USPS Domestic minimum Length
8.625
USPS minimum Width
5.375
USPS minimum Height
1.625
USPS International minimum Length
9.50
USPS minimum Width
1.0
USPS minimum Height
5.50
Enable USPS First-Class filter for US shipping
True
Shipping Methods (Domestic and International)
0, .21875, 0.00, 0, .8125, 0.00, 0, .8125, 0.00, 0, 70, 0.00, 0, 70, 0.00, Priority MailTM, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 15, 0.00, 0, 20, 0.00, 0, 25, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, 70, 0.00, 0, .21875, 0.00, 0, 4, 0.00, 0, 4, 0.00, 0, 66, 0.00, 0, 4, 0.00, 0, 4, 0.00, 0, 20, 0.00, 0, 20, 0.00, 0, 66, 0.00, 0, 4, 0.00, 0, 20, 0.00, 0, 70, 0.00, 0, 70, 0.00
Extra Services (Domestic)
Certified MailRM, N, USPS TrackingTM, N, Insurance, N, Priority Mail Express Insurance, N, Adult Signature Restricted Delivery, N, Adult Signature Required, N, Registered without Insurance, N, Registered MailTM, N, Collect on Delivery, N, Return Receipt for Merchandise, N, Return Receipt, N, Certificate of Mailing, N, Signature ConfirmationTM, N, Priority Mail Express 1030 AM Delivery, N
Extra Services (International)
Registered Mail, N, Insurance, N, Return Receipt, N, Electronic USPS Delivery Confirmation International, N, Certificate of Mailing, N
Retail pricing or Online pricing?
Online
Debug Mode
Logs***
If i take out zones, the ckeckout_shipping page show blank,
But PayPal works fine,
Zone name is Unite States, detail with states but not included island and Amy force,
***There is no shipping logs in cache, the latest one is 10/8/2013 ***
And i zip logs with winrar, it can not upload, sorry