Jump to global label, but all controls are disabled

Hello. I'm a total n00b at NSIS, and yet somehow have managed to make an installer that mostly works, much to NSIS's credit.

I have an installer that uses the MUI. I insert a custom page for getting user input using nsDialogs, and give the function a global label. Upon the intial iteration through the dialog it works fine. I then attempt to download a file using inetc, and if the download fails (any status other than "OK"), jump back to the global label to get the user input again.

When I jump back to the global label, the dialog renders, but all buttons are greyed out, including the red X in the corner of the installer. I have to CAD to kill the process.

I've attached the .nsi in question. If you want to test the resulting EXE, you can use install code 2502 for a correct install (this adds a signature file to Windows Mail in Vista only) or use 9999999 to make it fail.

I'm obviously doing something wrong, but I don't even know what to search for on the forums to resolve it. Any pointers (on this problem, or on improving my installer in general) would be welcome.

Installer attached, if you don't have the plugins to compile it with

see attached (inside zip file)

You cannot display custom pages while on another page.
I.e. You can only show pages in the show function [CustomPageShow] of Page Custom CustomPageShow CustomPageLeave

Stu