A new JIRA Database Values plugin has been released, see https://plugins.atlassian.com/plugin/details/4969 for download.
The major change is compatibility with JIRA 4.3.
There are some additional minor improvements like:
Use the internal JIRA db if no connection parameters are defined in the properties file
Honor the sort order used in the SQL query when using cascading comboboxes
Fix for Z-order if the AJAX popup appears over some other elements (thanks to Edgars Fabricius for providing a patch)