Comment 3 for bug 507973

Problem of the patch is that since OpenERP currently has no API to access & manipulate (physical) addons (most of their content anyway, there are a few functions in bin/addons but they're not really documented and usually not used), pretty much all addons and big parts of the core hit directly into config['addons_path'], considering it a single, physical path (e.g. os.path.join(config['addons_path'], 'crm', 'some', 'file', 'path'), also note that the possibility of the addon being zipped is completely ignored).

Therefore at this time and unless it's fixed everywhere (and there are lots of places, let me tell you) addons_path are completely broken.