I've released a new version that should work without any problems with Joomla 2.5. Please download it and test it and report any bugs that you find in the forums.
This new version also supports guest downloads/uploads. I'll update the documentation as soon as possible but for now the quick way to do it is to make a new user in Joomla and define it as the guest user in the component parameters.
So while I was enjoying my new site layout, I've decided to make a quick test on the component in Joomla 2.5.1. To my surprise, some gross problems were found so I've decided to review the extension before updating the content. I will also look into the guest access and external torrents to see if it's doable in a timely manner.
The site upgrade is done. Next step will be to update all the content with the latest information regarding the "com_tracker" extension.
I've also updated the com_tracker release due to some errors and minor bugs.