In order to add USPS V3 shipping module in your installed version of ViArt Shop, please do the following:
 
1. Download archive http://www.viart.com/downloads/va_add_usps_v3.zip;
2. Extract file usps_v3.php into the folder 'shipping' of your shop;
3. Extract file va_add_usps_v3.php into the root folder of your shop;
4. Run script http://your_site.com/va_add_usps_v3.php in Internet browser;
5. Delete file va_add_usps_v3.php from the root folder of the shop.
6. Enter Admin panel, go to Administration > Shipping Modules and check if it appeared in the listing under name USPS V3.
7. After installing this shipping module you can set it up with the same settings as in the old USPS module.
 
All releases which were issued after May 2007 already include this new USPS shipping module.

Ok, this makes sense, but doing it as you instructed did not change anything on my site. I look at the USPS "Edit Shipping Module" page, and it's still calling for
 
http://production.ShippingAPIs.com/ShippingAPI.dll..
 
Do I need to change this to something else to get USPS to return V3 options for my customers?
 
Ed
 
 

Hi Ed,
 
After appearing version 3 of USPS Rates API there was announced production URL
http://stg-production.shippingapis.com/ShippingAPI.dll
In the same time old version 2 USPS shipping module still uses
http://production.shippingapis.com/ShippingAPI.dll
 
WBR,
ViArt Support Team
 

From June, 6 2007 External URL for USPS module must be set again to:
http://production.shippingapis.com/ShippingAPI.dll - for production mode
and
http://testing.shippingapis.com/ShippingAPITest.dll - for testing purposes
 
WBR,
ViArt Support Team