I am just wondering if I got the manual wrong or if it's a bug in NSIS?
The manual (http://nsis.sourceforge.net/Docs/Chapter4.html#4.6.1) says at 4.6.1.2:
Begins and opens a new section. If section_name is empty, omitted, or begins with a -, then it is a hidden section and the user will not have the option of disabling it. If the section name is 'Uninstall' or is prefixed with 'un.', then it is a an uninstaller section.But if you name the section "Uninstall" and make it a hidden one ("-Uninstall") then it is no longer recognized as an uninstaller section. In this case you have to prefix it with "un." like any other uninstaller section.
IMHO this behaviour is at least a bit confusing and a remark in the manual may help ...!
Thanks
Gunther