[horde] Manage Notepads problem

[JP Edwards]

Hi,

When I click the:
[Manage Notepads] link

I get the following error message:

Not Found
The requested URL /mnemo/notepads/ was not found on this server.
Apache Server at webmail.unac.co.uk Port 80

The link that it's trying to follow is:
http://webmail.nnnservernnn.co.uk/mnemo/notepads/

I logged onto the server using putty and looked for 
the location /mnemo/notepads/ but it doesn't exist (which probably explains the error).

Application Versions are as follows:
Horde Horde (horde) 3.3.10
Mail Mail (imp) H3 (4.3.9)
Notes Notes (mnemo) H3 (2.2.4)

The server is a ubuntu 10.04 Lucid vps provided by webfusion with server management application Plesk and Virtuozzo. 

Horde comes preconfigured on this vps (but annoyingly missing some components e.g. nag and whups).

Anyone seen this error before or got a suggestion on how to fix it.  
I want to share the notepad with other users and also would like to create some other notepads but I can't because I can't get to the notepad management screen.

Thanks in advance for any suggestions offered,

JP.