Since I couldn't find a forum, I'll leave this here and hope that it's the right place.
Here's a small problem solution that might be interesting for people who can't release project versions in a fresh installation of Jira 4.4.4.
Problem: After installing a fresh Jira 4.4.4 32-bit I can create a new project versions without any troubles. Changing the project description afterwards or releasing the version is not possible, though. Once you commit your changes, the indicator circles forever and there is no feedback on your action. Everything else but managing versions seemed to work fine.
edit: removed the solution to add it as an answer, so this Question can be marked as solved.