New version is 06.6.00.0012. Updated USPS shipping which affected the main shipping library, the product add and edit managers, the shipping settings manager, and existing language default files.
Shipping methods were added: Priority Mail Commercial, Priority Express Mail Commercial, and Retail Ground (formerly Parcel Post in settings)
Ground is great for oversized packages under 70 lbs and for shipping slower to zones 5-9 in your shipping charts (usually 2-3+ states away from shipping origin).
International mail was fixed for Canada for combinations of extra services and shipping methods. Also fixed for first class package international that handles packages under 4 lbs at a better rate.
More service types were added for mostly domestic US shipments and also clarified in adding to ratings per package:
Return Receipt (updated, formerly delivery confirmation)
Signature Confirmation (updated)
Certificate of Mailing (new)
Special Handling - Fragile (new)
Regional Rate Box A (15 lbs max) & B (20lbs max) and ratings within Priority and Commercial methods added. Allows shipment of dense items over a short distance (ie: like a distributor sending cases of honey to a grocery store)
No caching header setting added to main settings manager under the misc tab to help reduce browser caching problems. If someone was visiting several pages frequently, the cart contents and inventory levels were not updating in the browser properly due to browser caching (memory of frequently visited pages and files). You can enable it if you notice such things happening. However, most visitors will not experience this problem.
Cart locking added to order logging routine. This also correlates to a PayPal IPN order lib update. This experimental fix helps only in very infrequent cases where orders were logging but with the cart contents missing from the order logs but still included in the admin and customer emails.