I'm having the same issue, but the variation in my case is price and I'm not getting any errors. It's simply not working.
Here is one page product as an example: http://skookummonkey.com/product/website-hosting-package-4-50000-mb-unlimited/
I already temp switched to the theme Twenty Thirteen to see if it was a theme compatibility issue, and the same problem exists. All non-variable items are working fine.
Here are my system details:
Home URL: http://skookummonkey.com
Site URL: http://skookummonkey.com
WC Version: 2.1.2
WC Database Version: 2.1.2
WP Version: 3.8.1
WP Multisite Enabled: No
Web Server Info: Apache/2.2.26 (Unix) mod_ssl/2.2.26 OpenSSL/0.9.8e-fips-rhel5 mod_bwlimited/1.4 PHP/5.4.25
PHP Version: 5.4.25
MySQL Version: 5.5.35-cll
WP Memory Limit: 64 MB
WP Debug Mode: No
WP Language: Default
WP Max Upload Size: 150 MB
PHP Post Max Size: 150 MB
PHP Time Limit: 30
PHP Max Input Vars: 1000
SUHOSIN Installed: No
WC Logging: Log directory is writable.
Default Timezone: Default timezone is UTC
fsockopen/cURL: Your server has fsockopen and cURL enabled.
SOAP Client: Your server has the SOAP Client class enabled.
WP Remote Post: wp_remote_post() was successful - PayPal IPN is working.
Installed Plugins: Akismet by Automattic version 2.5.9,
Contact Form 7 by Takayuki Miyoshi version 3.7.1,
Pizazz ExcerptsPlus (Headway 3 Block) by Chris Howard version 3.4.3,
Utility Block by Headway Labs version 1.3.3,
Jetpack by WordPress.com by Automattic version 2.8,
jQuery Smooth Scroll by BlogSynthesis version 1.2.4,
WooCommerce by WooThemes version 2.1.2,
WordPress Importer by wordpressdotorg version 0.6.1,
WP Maintenance Mode by Frank Bültge version 1.8.11,
wpsc Support Tickets PRO by wpStoreCart, LLC version 2.0.0,
wpsc Support Tickets by wpStoreCart, LLC version 4.3.2
Force SSL: No
Shop Base: #308 - /shop/
Cart: #309 - /cart/
Checkout: #310 - /checkout/
My Account: #311 - /my-account/
Order Statuses: cancelled (cancelled), completed (completed), failed (failed), on-hold (on-hold), pending (pending), processing (processing), refunded (refunded)
Product Types: external (external), grouped (grouped), simple (simple), variable (variable), virtual (virtual)
Theme Name: Custom Code for Skookum Monkey
Theme Version: 1.0
Author URL: http://skookummonkey.com
Template Overrides: No overrides present in theme.