Any Known SEF Issues?

Are there any known issues with a SEF/Rewritten URL, the checkout cart, and a currently logged in user?

It seems that if a user is logged in, and selects to purchase a product they are supplied the address selection step twice. If a user is currently logged in and selects a product to "add to cart" they are then redirected to the page for a shipping address (the beginning of the checkout process). After the user selects a shipping address, and clicks next they are taken to the address selection page again. From this point, if they select an address again (the second time) and click next, the next page is the payment page. Alternatively if the user is NOT logged-in everything works as desired.

products/checkout is the URL from the "add to cart" on the product page
products/checkout/checkout is the URL after selecting a shipping address
products/checkout/checkout/step/step-2 is the URL after selecting the shipping address a second time

Here's a Snippet of the Setup/Configuration
- Joomla (SEF URL's yes / URL Rewriting yes)
- One Shipping Method (manual) / Two Payment Methods (both PayPal IPN & Pro)
- SEF Url activate smaller URL yes
- Auto-Sumbit No
- Checkout Workflow login,address,shipping_payment_terms_cart,end
- The latest install of the Starter edition (and we recently purchased the Business edition which we will be upgrading to soon)

Auto select default shipping and payment methods = Yes

Edit - turning this off fixed the issue - thank you! This bug was driving me crazy.