Unable to install plugins via the web interface

[Kolgrath]

This happens in the standard AMP version as well as the Nightly Build for today.
What happens is when you select a plugin to install, it acts as if it is fully installing it.

However the file name for CoreProtect, for example, shows up in the plugin folder as 8631-v129564.jar.
It's the full plugin. It runs fine when starting the server. It just has that crazy name.
When clicking on Installed Plugins, the newly installed plugin does not appear.
Stopping and restarting the service shows that no plugins are installed, even though the above mentioned jar is in the plugins folder.

Expected (Or hopeful?) behavior:
Clicking on Install for a plugin will download the jar file without renaming it. So mcMMO.jar keeps its name. Then when clicking on Installed Plugins it shows the plugin correctly and as being managed by AMP.