When enabling 'Varnish Pages' cache, get simplexml_load_string parser error

Using turpentine 0.6.0 release on 1.11.2.0, with varnish 3.0.5 on CentOS 6.5, running PHP 5.4.31 via PHP-FPM. There's a large number of extensions, but none that should interact with caching or the config (beyond configuring themselves).

Warning: simplexml_load_string(): Entity: line 41: parser error : StartTag: invalid element name  in /var/www/lib/Varien/Simplexml/Config.php on line 383

#0 [internal function]: mageCoreErrorHandler(2, 'simplexml_load_...', '/var/www/...', 383, Array)
#1 /var/www/lib/Varien/Simplexml/Config.php(383): simplexml_load_string('loadCache()
#3 /var/www/app/code/core/Mage/Core/Model/App.php(408): Mage_Core_Model_Config->loadModulesCache()
#4 /var/www/app/code/core/Mage/Core/Model/App.php(338): Mage_Core_Model_App->_initModules()
#5 /var/www/app/Mage.php(640): Mage_Core_Model_App->run(Array)
#6 /var/www/index.php(87): Mage::run('', 'store')
#7 {main}

If I don't enable the Varnish cache in the Magento Cache admin page, then this error doesn't occur, and the site works normally (with Varnish doing not much of course). EE's FPC is disabled. Enabling just 'Varnish Pages' without 'Varnish ESI Blocks' also has this error, so it seems to be specific to 'Varnish Pages'.

codePool	Name	Version	Status
community	AddThis_SharingTool	1.0.0	active
community	Amplifi_CatalogProductAttributeNote		active
community	Amplifi_CoreDesignPackageCascade	0.1.0	active
community	Amplifi_Deployment		active
community	Amplifi_DisableCompare	0.1.0	active
community	Amplifi_EnableSmtp	0.1.0	active
community	Amplifi_Integration		active
community	Find_Feed	0.0.2	active
community	Fishpig_Wordpress	2.4.65	active
community	Fishpig_Wordpress_Addon_AllInOneSEO	1.0.0	active
community	Fishpig_Wordpress_Addon_WordPressSEO	1.0.0	active
community	Fooman_AdvancedPromotions	1.1.16	active
community	Fooman_Common	1.0.0	active
community	Nexcessnet_Turpentine	0.6.0	active
community	Phoenix_Moneybookers	1.6.0.0	active
community	Springbot_Bmbleb	0.1.0	active
community	Springbot_BoneCollector		active
community	Springbot_Combine	1.2.0.0	active
community	Springbot_Shadow		active
community	TBT_Billboard	0.1.0.0	active
community	TBT_Common	0.1.0.0	active
community	TBT_Milestone	0.1.2.0	active
community	TBT_Rewards	1.8.3.0	active
community	TBT_RewardsApi	1.0.0.0	active
community	TBT_RewardsCoreCustomer	1.0.0.0	active
community	TBT_RewardsCoreSpending	1.0.0.0	active
community	TBT_RewardsLoyalty	0.2.0.0	active
community	TBT_RewardsOnly	1.0.0.1	active
community	TBT_RewardsPlat	1.7.5.3	active
community	TBT_RewardsReferral	3.2.1.0	active
community	TBT_Rewardssocial	1.0.0.8	active
community	TBT_Testsweet	1.0.1.2	active
community	Unirgy_SimpleLicense	1.0.2	active
community	Unirgy_SimpleUp	1.0.2	active
community	Unirgy_StoreLocator	2.1.2	active
community	Webshopapps_Desttype	0.0.3	active
community	Webshopapps_Ordermanager	0.0.1	active
community	Webshopapps_Wsalogger	1.0.2	active
local	AmplifiLocal_AdRoll	0.1.0	active
local	AmplifiLocal_Adminhtml	0.1.0	active
local	AmplifiLocal_Catalog	0.1.0	active
local	AmplifiLocal_Cms	0.1.0	active
local	AmplifiLocal_Dealdesk	0.1.0	active
local	AmplifiLocal_DesignPackageSetStoreBugfix	0.1.0	active
local	AmplifiLocal_GridActions	0.1.0	active
local	AmplifiLocal_ProductAttributes	0.1.0	active
local	AmplifiLocal_Sales	0.1.0	active
local	AmplifiLocal_ShippingLabel	0.1.0	active
local	AmplifiLocal_Usa	0.1.0	active
local	AmplifiLocal_Wordpress	0.1.0	active
local	Evolved_Like	1.6.2	active
local	Mage_LoadTest		active
local	Webshopapps_Shippingoverride2	0.0.6	active
local	Webshopapps_Wsacommon	1.0.0	active
local	Xtento_GridActions	1.2.5	active
local	Xtento_XtCore	1.0.0	active

nexcess / magento-turpentine

When enabling 'Varnish Pages' cache, get simplexml_load_string parser error #625