Magento

Hi, we are upgrading from 1.6 to 1.7 and have noticed erratic/odd behavior post-upgrade:

1) Loss of customer first/last names, all other customer data intact.
2) Loss of category names, URL keys, and design data, all other data intact.
3) Loss of prices/inventory on products, all other data intact.
4) Really weird exception fix by moving placement of a bracket in Mage_Catalog_Model_Product.

Has anybody else found behavior like this post-upgrade?  Did you ever find the root cause?  Thanks.