Checkout Errors with Products with Attributes and Tax Cloud plugin

I am running a new install of v1.5.0, PHP Version: 5.3.18, MySQL v. 5.0.77, with the Andover Modern template on a dev site. I have installed Tax Cloud v1.5.

I did not try to checkout until I added Tax Cloud. When I checkout with a product in my cart that does NOT have attributes I can complete the checkout process. When a product HAS attributes I can look at my cart, choose to checkout, log into my account (if I'm not already logged in) and then I receive "WARNING: An Error occurred, please refreshå the page and try again."

When I look at the error log it says:
"[17-Jan-2013 12:46:22 America/New_York] PHP Fatal error: 1054:Unknown column 'poval.products_options_values_name' in 'field list' :: select popt.products_options_name, poval.products_options_values_name,
pa.options_values_price, pa.price_prefix
from products_options popt,
products_options_values poval,
products_attributes pa
where pa.products_id = '840'
and pa.options_id = '52'
and pa.options_id = popt.products_options_id
and pa.options_values_id = '126'
and pa.options_values_id = poval.products_options_values_id
and popt.language_id = '1'
and poval.language_id = '1' in /home/tszen/www/includes/classes/db/mysql/query_factory.php on line 101"

Additionally, when I try to look at a product's attributes in the Attribute Controller this message shows up under the Legend and I cannot view the actual attribute:
"WARNING: An Error occurred, please refresh the page and try again.
1 |"

Any help in pointing me in the correct direction to solving this error will be appreciated. Thanks.

I see that for some reason the title does not correctly reflect my problem. I would swear I never wrote that title - I had written "Checkout Errors with Products with Attributes." I only discovered this a day after posting and apparently it is too late to edit or even delete this post and repost under the correct title. If a monitor reads this can you please change the title for me? Thanks.

Post title changed.

How certain are you that this isn't related to Tax Cloud? Why so?

The error message literally means that your products_options_values table is missing the products_options_values_name field. And that field is present in every version of Zen Cart released in the last 8 years ... unless you've changed it either by deleting it yourself or using some mod that has significantly altered the database.