TortoiseBZR doesn't set itself to approved shell extension list.

TBZR doesn't set itself to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Shell Extensions\Approved

see http://msdn.microsoft.com/en-us/library/cc144110(VS.85).aspx

--- original question ---
I've installed Bazaar using the 2.1.0.2 windows installer, and included TortoiseBZR. I can see the icon in the tray, I can see processes called tbzrcachew.exe and tbzrcommandw.exe in the task manager, and files in my test repo created from the command line have shellicons, but I can't see any context menu for Bazaar.
I've tried running tbzrtrace.exe and then accessing the context menu but nothing comes out in the trace.

I'm running Windows XP Pro (32 bit). Not sure if this might have an impact, but my usual login does *not* have admin rights, I have to install Bazaar with a different account. I also have TortoiseSVN, TortoiseHg and TortoiseGit all installed (yes, DVCS evaluation phase is under way).

What I'm expecting is that in an empty folder I get a limited set of BZR commands in the Windows context menu, e.g. init, while in a folder inside a checkout I get more options.