[imp] File does not exist

[John Peach]

Hello:

I have a fresh install of horde 5.0.4 and imp 6.0.4 When I try to access any the
mail function I get the following to errors in the error log

[Sat Mar 16 17:38:02 2013] [error] [client 169.229.121.134] File does not exist:
/home/services/horde/public_html/services/ajax.php/imp/listMailboxes, referer:
https://webmail.jppeach.net/imp/dynamic.php?page=mailbox
[Sat Mar 16 17:38:02 2013] [error] [client 169.229.121.134] File does not exist:
/home/services/horde/public_html/services/ajax.php/imp/viewPort, referer:
https://webmail.jppeach.net/imp/dynamic.php?page=mailbox

Apache is complaining that the following files do not exist:
/home/services/horde/public_html/services/ajax.php/imp/listMailboxes
/home/services/horde/public_html/services/ajax.php/imp/viewPort

The file /home/services/horde/public_html/services/ajax.php exists.  

There is no file called listMailboxes or viewPort, looking at the code they
appear to be methods.

Any ideas on how I can track this down?