Horde Access Issue

[digitaldose]

Hi Everyone.
I just installed a clean version of Plesk 8.6 on Linux and I having an issue with access to Horde via webmail.plaindomain.com. When you navigate to the address it wants to open and download what I think is the "login.php" file. I've tried to resolve the issue myself but have run out of options.

Here is a link to the screen shot. http://www.ifiddy.com/suse/pleskhorde.png

Thanks in advance for your suggestions.