I had a client site using banners, configured to register clicks on each banner. The client discovered that sometimes clicks was not registered on the correct banner. Initially it looked like banners with the same target link (URL) was registered on the banner with the lowest ID. This turned out to be misleading.
The cause was a SEF plugin called JoomSEF. This plugin handled the URL:s also for banners routing the clicks to the wrong banner.
The solution was to exclude Joomla banner component from being handled by JoomSEF:
- Go to Components -> JoomSEF -> Manage Extensions
- For Banners, click to the right so it displays Default Joomla router under Active Handler