The JEvents 2.0.11 is now available from the download area - this version is designed to be compatible with Joomla 1.5, 1.6 and 1.7. It fixes a theoretical XSS vulnerability found in JEvents 1.5.0 onwards - you are encouraged to upgrade as soon as possible.
As well as being compatible with Joomla 1.6/1.7, JEvents 2.0 allows you to configure categories to block overlapping events from being created. This can also be applied to event venues using the managed locations club addon.
Most of the club addons have now been migrated to be compatible with Joomla 1.6 (see this forum post for more detail).