Invalid Class String

I am trying to use the File->Send To->Mail Recipient option from Office 2000 applications to send an email (and attachment) using Lotus Notes, and I get the following error:-

Invalid Class String

Lotus Notes is my default mail program. I have checked the following:

In Notes Client, under User prefs, the option “Enable MS Office 97 sendto to notes” is checked.

In IE (v6.0) under programs, the email program is set to Lotus Notes.

In Win2K, Start->Set Program Access and defaults, “Choose a default email program” is set to “Use my current…”

The following Registry settings are correct.

[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail]

[HKEY_CLASSES_ROOT\mailto\Shell\Open\Command]

@=“C:\lotus\notes\notes.exe %1”

Thanks

Paul