"The Joomla Project is pleased to announce the immediate availability of Joomla 1.5.8 [Wohnaiki]. This release contains a number of bug fixes and two moderate-level security fixes. It has been around two months since Joomla 1.5.7 was released on September 9, 2008."
Joomla 1.5 templates from our team are fully compatible with Joomla 1.5.8
Check release notes