I have written several new classes for a much improved UPS shipping module. I have tested them with isolated scripts and they perform as expected. I have matched the return types with that from the ups.php getquote().
The new classes work for the checkout page Step 1 0f 3. However, ANY CHANGES AT ALL seem to prevent a successful Step 2 of 3. This only happens if you select one of the UPS shipping options. The entire new class script is run (used numerous echo commands to be sure) but the page never shows. The simple "require_once" statement below is enough to stop things from working even though the full class script executes. I am at a loss of where to go from here. The code works for shopping the rates, but will go no farther.
if ($method) $this->_upsAction('3'); // return a single quote
// ups doesnt accept zero weight send 1 ounce (0.0625) minimum
$ups_shipping_weight = ($shipping_weight <= 0 ? 0.0625 : $shipping_weight);
require_once (DIR_WS_CLASSES . 'upsRateClass.php');
$country_name = zen_get_countries(SHIPPING_ORIGIN_COUNTRY, true);
$upsQuote = $this->_upsGetQuote();