Essentially, the removeModule method of the ServletModuleManager class in atlassian-plugins is broken; it removes the paths (and that's debatable, as the removeMappingsForKey method in seraph's PathMapper class only removes from complexPaths (possibly incorrectly) and ignores mappings - leaving the mapping there) but crutially leaves the inittedServlets map alone.

I suspect that adding "inittedServlets.remove(descriptor.getCompleteKey());" to the removeModule method will sort the problems I am getting ... however that will certainly mask the path mapping issue which will need to be checked (just to be sure).

Steps to repo:

1. upload to confluence plugin 1
2. goto the URL (should read: Hello World!)
3. uninstall and upload plugin 2 (enable if needed)
4. goto the URL (should still read: Hello World!)
5. restart confluence
6. goto the URL (should read: Hello Mum!)